Taurine suppresses gastric intestinal metaplasia in patient-derived organoids and Atp4a-/- mice

Abstract

BACKGROUND

Gastric intestinal metaplasia (GIM) represents a critical precancerous condition in the progression from chronic gastritis to gastric cancer, with limited therapeutic options. Emerging evidence suggests that taurine, a cytoprotective amino acid, may modulate gastric epithelial dysfunction. However, its application and efficiency in the context of GIM remain poorly understood.

AIM

To investigate the therapeutic effects of taurine on GIM using patient-derived organoids and Atp4a^-/- mouse models.

METHODS

Patient-derived GIM organoids (n = 3) and Atp4a^-/- mice, which spontaneously develop GIM, were used as experimental models. Morphological changes were assessed via Alcian blue-periodic acid Schiff staining. The expression levels of the gastric epithelial marker mucin 5AC (MUC5AC) and GIM-associated markers (caudal type homeobox 2 [CDX2], MUC2, Trefoil factor family 3 [TFF3]) were quantified via quantitative PCR, Western blotting, and immunohistochemistry.

RESULTS

We confirmed that taurine treatment significantly attenuated pathological changes, including glandular hypertrophy and vacuolar dilation, in Atp4a^-/- mice. It also reduced GIM severity compared with that in the untreated model group. Under taurine treatment, MUC5AC expression was significantly increased, whereas the intestinal-specific markers CDX2, MUC2, and TFF3 were reduced (P < 0.05). In parallel, in patient-derived GIM organoids, taurine treatment significantly ameliorated GIM features, as evidenced by increased MUC5AC expression and decreased CDX2, MUC2, and TFF3 expression.

CONCLUSION

This study highlights the potential application of taurine as a therapeutic agent for treating GIM, offering a promising strategy for its clinical management.

Key Words: Atp4a gastric intestinal metaplasia models; Biomarkers; Gastric intestinal metaplasia; Organoid; Taurine

Core Tip: Limited treatments for gastric intestinal metaplasia (GIM) are available. This study used Atp4a^-/- mice (spontaneous GIM models) and patient-derived GIM organoids to show that taurine ameliorates GIM. It reduces murine gastric mucosal lesions, upregulates the gastric marker mucin 5AC (MUC5AC), and downregulates intestinal markers (caudal type homeobox 2, MUC2, and Trefoil factor family 3) in both models, suggesting a novel GIM therapeutic strategy.

INTRODUCTION

Gastric intestinal metaplasia (GIM) is a well-established risk factor for intestinal-type gastric cancer (GC), with a global prevalence ranging from 5% to 20%. In East Asia, approximately 0.25%-10% of patients with GIM progress to GC annually[1]. As a high-incidence region for GC, China has a markedly higher prevalence of GIM than the global average does, largely attributable to dietary habits and potential genetic susceptibility, with rates in Chinese adults reaching 23%[2,3]. Recognized as a precancerous lesion, GIM is considered a critical target for preventive strategies, and its reversal may hold substantial clinical value in reducing the burden of GC. The major etiological factors of GIM include Helicobacter pylori infection, a high-salt diet, smoking, and bile reflux[4]. Nevertheless, current clinical practices lack effective approaches for reversing GIM, with available strategies mainly confined to H. pylori eradication (bismuth-containing quadruple therapy) and endoscopic surveillance[5,6]. Consequently, the development of novel targeted interventions is highly important for preventing the progression of GIM to GC.

Taurine is a conditionally essential micronutrient that is widely distributed in mammalian tissues and is abundant in various foods. Functionally, it exerts pleiotropic regulatory effects on cellular processes and plays a pivotal role in maintaining systemic metabolic homeostasis[7-9]. Genetic depletion of taurine has been shown to induce a spectrum of pathological alterations, including muscle atrophy, impaired exercise capacity, and mitochondrial dysfunction across multiple tissues[10,11]. Conversely, exogenous taurine supplementation has demonstrated clear beneficial effects[12]. Taurine uptake in most cells is mediated by the sodium/chloride-dependent transporter solute carrier family 6 member 6[13-15]. Emerging evidence indicates that taurine supplementation suppresses the growth of colon, cervical, and endometrioid carcinoma cells and enhances GC therapy by potentiating antitumor immunity[16-20]. Despite these advances, its regulatory role in GIM, a critical precancerous stage in the Correa cascade, remains unexplored.

Traditional cell lines have considerable limitations in recapitulating in vivo physiological and pathological conditions. In recent years, three-dimensional organoid models have emerged as powerful tools in digestive disease research[21,22]. These organ-specific cultures, derived from epithelial stem cells, faithfully preserve the functional and molecular features of their tissue of origin and can be stably propagated in vitro without the loss of key characteristics[23-25]. Despite these advances, organoid models derived from GIM remain scarce. Acid-secreting activity mediated by H⁺-K⁺-ATPase is critical for the survival and proper development of gastric parietal cells. Genetic ablation of the H⁺-K⁺-ATPase α-subunit in Atp4a^-/- mice results in chronic achlorhydria beginning at approximately 12 weeks of age, accompanied by glandular hyperplasia and vesicle formation. Over time, persistent inflammation leads to basal mucosal atrophy and the onset of GIM[26,27].

To address this knowledge gap, we designed a study to systematically evaluate the therapeutic potential of taurine in attenuating GIM. A dual-model strategy was adopted to gain both mechanistic insight and translational relevance: The Atp4a^-/- murine model, which genetically mirrors critical aspects of GIM progression, and patient-derived organoids, which provide a clinically relevant ex vivo human system. We hypothesized that taurine supplementation would ameliorate GIM by restoring gastric epithelial identity, specifically through the downregulation of intestinal markers (caudal type homeobox [CDX2], mucin 2 [MUC2], and Trefoil factor family 3 [TFF3]) and the upregulation of the gastric lineage marker MUC5AC. Our findings demonstrated that taurine effectively suppressed GIM in both models, underscoring its potential as a novel therapeutic agent for the clinical management of this precancerous lesion.

MATERIALS AND METHODS

Patients

Three patients with pathologically confirmed GIM were enrolled, from whom both GIM lesion tissues and adjacent normal gastric mucosa were collected. The inclusion criteria included a definitive diagnosis of GIM by gastroscopic biopsy or surgical pathology and complete clinical records, including H. pylori infection status and medication history. Patients with a history of GC, previous gastric radiotherapy or chemotherapy, autoimmune gastritis, or recent use of proton pump inhibitors, nonsteroidal anti-inflammatory drugs, or immunosuppressants within three months were excluded. Pregnant individuals and those with mental disorders that might compromise compliance were also excluded. Detailed patient information is summarized in Supplementary Table 1.

Animals

Atp4a^-/- mice were generated via the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 system (Shanghai Model Organisms Center, Shanghai, China) and maintained in a specific pathogen-free facility under controlled conditions (50%-60% relative humidity, 22 °C ± 3 °C temperature, and a 12-hours light/dark cycle). Six wild-type (WT) C57BL/6 mice (Beijing Vital River Laboratory Animal Technology Co., Ltd., Beijing, China) served as the control group, whereas 12 Atp4a^-/- mice were randomly assigned to either the model group or the taurine treatment group. The mice in the treatment group received taurine (MedChemExpress, Monmouth Junction, NJ, United States) ad libitum in the drinking water at 1000 mg/kg/day beginning at 12 weeks of age[28]. After 4 weeks of treatment, the gastric tissues were harvested for subsequent analyses.

Pathological examination

Gastric tissues were fixed in 4% paraformaldehyde and subsequently dehydrated through a graded ethanol series (75%-95%), cleared in xylene, and embedded in paraffin. The paraffin blocks were sectioned at a thickness of approximately 4 μm. The tissue sections were stained with a hematoxylin and eosin staining kit (Solarbio, Beijing, China) and an Alcian blue-periodic acid Schiff (AB-PAS) staining kit (Solarbio) to evaluate histopathological alterations in the gastric tissues.

Immunohistochemistry

The gastric tissue sections were dewaxed, rehydrated, and incubated with primary antibodies against MUC5AC (1:200, GTX11335; GeneTex, Irvine, CA, United States), CDX2 (1:100, ab101532; Abcam, Cambridge, United Kingdom), MUC2 (1:2000, 27675-1-AP; Proteintech, Wuhan, China), and TFF3 (1:800, 23277-1-AP; Proteintech). Immunostaining was performed via a universal two-step detection kit (mouse/rabbit enhanced polymer system; ZSGB-Bio, Beijing, China), followed by hematoxylin counterstaining (Celnovte Biotechnology, Zhengzhou, China). Protein expression was evaluated according to the German semiquantitative scoring system. The staining intensity was graded as 0 (negative), 1 (light yellow), 2 (brown), or 3 (dark brown), while the proportion of positive cells was scored as 0 (< 5%), 1 (5%-24%), 2 (25%-49%), 3 (50%-74%), or 4 (≥ 75%). The final score was calculated as the product of intensity and proportion scores. All slides were independently assessed by two pathologists blinded to the experimental groups, and the mean values were used for statistical analyses[29].

Organoids derived from patients with human GIM

Human gastric organoids were generated from both normal gastric mucosa and GIM tissues obtained from endoscopic biopsies or surgical specimens. The tissues were washed thoroughly in cold phosphate-buffered saline containing 1% penicillin-streptomycin and then minced into approximately 1 mm³ fragments. Tissue fragments were digested in 5 mL of advanced Dulbecco’s Modified Eagle's Medium (DMEM)/F12 medium containing 1 mg/mL collagenase XI, 10 μM Y-27632 (Rho-associated protein kinase inhibitor), and 1% fetal bovine serum for 60-90 minutes at 37 °C with gentle agitation.

After digestion, the cell suspension was filtered through a 100-μm cell strainer and centrifuged at 300 × g for 5 minutes. The pellet was resuspended in cold Matrigel (Corning, Corning, NY, United States) at a density of approximately 1 × 10⁴ cells per 30 μL Matrigel droplet. Each 30 μL Matrigel droplet was plated in the center of a pre-warmed 24-well plate and polymerized at 37 °C for 15-20 minutes.

Following polymerization, 500 μL of complete human gastric organoid culture medium was added to each well. The culture medium consisted of advanced DMEM/F12 supplemented with 1 × B27, 1 × N2, 10 mmol/L HEPES, 1 mmol/L N-acetylcysteine, 10% R-spondin conditioned medium, 100 ng/mL Noggin, 50 ng/mL EGF, 10% Wnt3a conditioned medium, 10 μM Y-27632, and 1% penicillin-streptomycin. The medium was changed every 2-3 days, and organoids were passaged every 7-10 days using mechanical disruption and re-embedding in fresh Matrigel. All organoid cultures were maintained at 37 °C in a humidified incubator with 5% carbon dioxide[30-32].

Real-time fluorescence quantitative PCR

Total RNA was extracted via TRIzol reagent (Thermo Fisher Scientific, Waltham, MA, United States), and complementary DNA (cDNA) was synthesized via the HiScript II 1^st Strand cDNA Synthesis Kit (Vazyme, Nanjing, China) according to the manufacturer’s protocol. Quantitative PCR was performed via SYBR Green PCR Master Mix (Vazyme), and relative gene expression levels were determined via the 2^-ΔΔCt method[33]. The primer sequences are provided in Supplementary Table 2.

Western blot analysis

Total protein was extracted from organoids via RIPA buffer (Solarbio), and protein concentrations were determined with a Bicinchoninic Acid Assay Kit (Solarbio). Protein lysates were mixed with 5 × sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) loading buffer, boiled at 100 °C for 5 minutes, and separated on 5%-10% SDS-PAGE gels, followed by electrotransfer to polyvinylidene difluoride membranes. The membranes were blocked in 5% nonfat milk at room temperature for 2 hours, incubated with primary antibodies overnight at 4 °C, washed with Tris-buffered saline containing Tween 20, and then incubated with secondary antibodies for 1 hour at room temperature. The protein bands were visualized via enhanced chemiluminescence reagent (Meilunbio, Shanghai, China) and imaged with the ChemiDo^TM XRS+ system (Bio-Rad, Hercules, CA, United States). The primary antibodies used included rabbit anti-CDX2 (1:1000, ab101532; Abcam), rabbit anti-TFF3 (1:800, 23277-1-AP; Proteintech), and rabbit anti-β-tubulin (1:2000, 10994-1-AP; Proteintech).

Statistical analyses

All of the statistical analyses were conducted via GraphPad Prism 9.0 software (GraphPad Software, San Diego, CA, United States). The data are presented as the means ± standard deviations from at least three independent experiments. The Shapiro-Wilk test was applied to assess data normality. For normally distributed data with homogeneity of variance, comparisons between two groups were performed via an independent samples t-test, whereas comparisons among three or more groups were analyzed via one-way analysis of variance. When normality or variance assumptions were not satisfied, the Kruskal-Wallis test was employed. P < 0.05 was considered statistically significant.

RESULTS

Establishment and identification of a murine metaplasia model

To validate the reliability of the Atp4a^-/- mouse model for GIM research, we compared gastric mucosal morphology and histological features between 12-week-old Atp4a^-/- mice and WT C57BL/6 mice (n = 6 per group). In WT mice, the gastric mucosa appeared smooth and flat with a uniformly pale pink surface and a well-organized structure, without vacuolar changes or abnormal cell types. By contrast, Atp4a^-/- mice presented pronounced abnormalities, including rough and uneven mucosal surfaces, disordered epithelial cell arrangement, disrupted glandular architecture, enlarged glandular ducts, and extensive vacuolar dilatations (Figure 1A). The vacuolar dilatations observed in the gastric mucosa of Atp4a^-/- mice represent dilated intracellular compartments within gastric mucous cells. These structures appear as clear cytoplasmic spaces that disrupt normal glandular architecture. Histologically, they differ from non-dilated regions by their enlarged size and membrane-bound appearance. Periodic acid Schiff (PAS) staining of WT gastric mucosa revealed abundant neutral mucins, while AB-PAS staining was negative, which is consistent with the absence of intestinal-type epithelium[34]. In Atp4a^-/- mice, however, numerous gastric glands exhibited blue-purple staining with AB-PAS, reflecting the coexistence of neutral and acidic mucins (Figure 1B). Together, these morphological and histological findings confirmed that Atp4a^-/- mice spontaneously develop characteristic GIM pathology.

Figure 1 Identification of the gastric intestinal metaplasia mouse model and the effects of taurine intervention. A: Hematoxylin and eosin staining of the mouse gastric mucosa (n = 6); B: Alcian blue-periodic acid Schiff staining of the mouse gastric mucosa (n = 6); C: Relative expression levels of gastric intestinal metaplasia-related genes detected by quantitative PCR (qPCR; n = 6); D: Relative expression level of MUC5AC detected by qPCR (n = 6). ^aP < 0.05 vs wild-type (WT); ^bP < 0.01 vs WT; ^cP < 0.05 vs Atp4a^-/-; ^dP < 0.01 vs Atp4a^-/-.

Regulation of GIM marker expression in the gastric tissues of Atp4a^-/- mice by taurine

To evaluate the therapeutic effect of taurine on GIM in Atp4a^-/- mice, three groups were established: WT, Atp4a^-/-, and Atp4a^-/- + taurine intervention. Histological analyses revealed marked improvement in gastric mucosal pathology in the intervention group. Compared with those of the model group, the mucosal surface was smoother, epithelial cell disorganization was alleviated, the number of enlarged glandular ducts and vacuolar dilatations was significantly lower, glandular structures regained regularity, mucosal integrity was restored, and the overall morphology more closely resembled that of the WT group (Figure 1A). Moreover, the blue-purple regions indicative of acidic mucins were markedly diminished, whereas PAS-positive neutral mucins (fuchsia) expanded, suggesting a partial reversion toward the normal gastric mucosal phenotype (Figure 1B).

To further clarify the molecular basis of the effects of taurine, we measured the relative mRNA expression of intestinal epithelial markers (CDX2, MUC2, TFF3) and the gastric mucosal marker MUC5AC, with glyceraldehyde-3-phosphate dehydrogenase as the internal control[35-37]. In the Atp4a^-/- model group, CDX2 (a transcription factor that initiates intestinal metaplasia), MUC2 (an intestinal mucin produced by goblet cells), and TFF3 (an intestinal repair factor reflecting GIM severity) were significantly upregulated compared with those in the WT group (P < 0.05). Taurine intervention significantly reduced the expression of these markers (P < 0.05; Table 1, Figure 1C). MUC5AC, a gastric mucin secreted by surface mucous cells, was downregulated in the model group but not significantly (P > 0.05); however, taurine treatment led to a significant increase in MUC5AC expression (P < 0.05; Table 1, Figure 1D). These findings indicate that taurine delays GIM progression and promotes recovery of the gastric mucosal phenotype by suppressing intestinal epithelial marker transcription and enhancing gastric-specific mucin expression.

Table 1 Summary of molecular marker expression changes in the Atp4a^-/- mouse model after taurine intervention.

Marker	Type	Function	WT expression	Model expression vs WT	Taurine intervention expression vs model	P value (taurine vs model)	Detection method
CDX2	Intestinal transcription factor	Regulates intestinal metaplasia initiation	Baseline	Upregulated (significant)	Downregulated (significant)	< 0.05 (mRNA), < 0.0001 (protein)	qPCR, IHC
MUC2	Intestinal mucin	Goblet cell product in intestinal epithelium	Baseline	Upregulated (significant)	Downregulated (significant)	< 0.05 (mRNA), < 0.01 (protein)	qPCR, IHC
TFF3	Intestinal repair factor	Associated with GIM severity	Baseline	Upregulated (significant)	Downregulated (significant)	< 0.05 (mRNA), < 0.01 (protein)	qPCR, IHC
MUC5AC	Gastric mucin	Surface mucous cell product	Baseline	Downregulated (nonsignificant at mRNA)	Upregulated (significant)	< 0.05 (mRNA), < 0.001 (protein)	qPCR, IHC

CDX2: Caudal type homeobox 2; GIM: Gastric intestinal metaplasia; IHC: Immunohistochemistry; MUC2: Mucin 2; MUC5AC: Mucin 5AC; qPCR: Quantitative PCR; TFF3: Trefoil factor family 3; WT: Wild-type.

The protein expression and distribution of the above markers were also examined. In WT mice, CDX2-positive cells were virtually absent throughout the gastric mucosa, whereas abundant CDX2-positive cells were observed in the Atp4a^-/- model group. Taurine intervention markedly reduced the number of CDX2-positive cells, with staining restricted to the focal glandular epithelium (P < 0.0001; Table 1, Figure 2A and B). MUC2 and TFF3 showed similar expression patterns (P < 0.01;Table 1, Figure 2A and B). By contrast, the MUC5AC-positive areas were significantly smaller and weakly stained in the model group than in the WT group, but the staining intensity was restored following taurine treatment (P < 0.001; Table 1, Figure 2A and C). Together, these results confirm that at both the transcriptional and protein levels, taurine alleviates GIM in Atp4a^-/- mice by downregulating the expression of intestinal epithelial markers and increasing the expression of the gastric mucosal marker MUC5AC.

Figure 2 Taurine increases the mucin 5AC (MUC5AC) level and inhibits the expression of caudal type homeobox 2, MUC2, and Trefoil factor family 3 in Atp4a^-/- mice. A: Expression of caudal type homeobox 2 (CDX2), mucin 2 (MUC2), Trefoil factor family 3 (TFF3) and MUC5AC in Atp4a^-/- mouse gastric tissues was assessed via immunohistochemistry (IHC) staining (n = 6); B: IHC scores of CDX2, MUC2, and TFF3 (n = 6); C: IHC score of MUC5AC (n = 6). ^aP < 0.01 vs Atp4a^-/-; ^bP < 0.01 vs wild-type (WT).

Culture and identification of GIM organoids

To further validate the effectiveness of taurine in a human-derived system, minimize the influence of interspecies differences on data interpretation, and establish a clinically relevant GIM research platform, we cultured and characterized human-derived GIM organoids (Figure 3A). Three patients who were diagnosed with GIM via gastroscopic biopsy were enrolled. To define the molecular phenotype of GIM organoids, we analyzed marker expression at both the mRNA and protein levels in three paired samples (GIM organoids vs normal gastric mucosal organoids from the same patient). In all 3 patients, the relative expression of CDX2, MUC2, and TFF3 was significantly greater in GIM organoids than in their normal counterparts (P < 0.05), whereas MUC5AC expression was significantly lower (Table 1, Figures 3B-M and 4).

Figure 3 Effects of taurine on gastric intestinal metaplasia organoids. A: Typical growth progression of normal human gastric organoids over 7 days in culture; B-E: Expression levels of gastrointestinal-related markers in patient 1; F-I: Expression levels of gastrointestinal-related marker genes in patient 2; J-M: Expression levels of gastrointestinal-related marker genes in patient 3. ^aP < 0.05 vs normal control (CON); ^bP < 0.01 vs normal CON; ^cP < 0.001 vs normal CON; ^dP < 0.05 vs gastric intestinal metaplasia (GIM) control; ^eP < 0.01 vs GIM CON.

Figure 4 Taurine downregulates the protein expression of caudal type homeobox 2 and Trefoil factor family 3 in gastric intestinal metaplasia control organoids. A-C: Western blotting was conducted to assess the protein levels of caudal type homeobox 2 (CDX2) and Trefoil factor family 3 (TFF3); D-I: Relative protein levels were quantified. ^aP < 0.01 vs normal control; ^bP < 0.05 vs gastric intestinal metaplasia (GIM) control (CON); ^cP < 0.01 vs GIM CON.

These findings confirm the successful establishment of a human-derived organoid model that faithfully reproduces the molecular features of GIM, characterized by the upregulation of intestinal epithelial markers and the downregulation of gastric mucosal markers. This model not only reflects the shared molecular patterns of GIM across different patients but also provides a reliable in vitro platform for investigating the therapeutic potential of taurine and elucidating the mechanisms underlying GIM pathogenesis.

Improvement in the GIM characteristics of patient-derived GIM organoids by taurine

To evaluate the effect of taurine on GIM in a human-derived in vitro model, both normal gastric mucosal organoids and GIM organoids were divided into two subgroups. The average plasma taurine concentration is approximately 80 mmol/L[13]. To increase the level of intracellular taurine, the organoids were cultured either in medium supplemented with 200 mmol/L taurine or in basal medium without taurine. After 1 week of continuous intervention, the following results were obtained. Compared with those in the corresponding control group, the expression levels of CDX2, MUC2, and TFF3 in the GIM organoid intervention group were significantly lower (P < 0.05; Table 2, Figures 3B-D, 3F-H, 3J-L and 4). In addition, MUC5AC expression was significantly upregulated in patients 1 and 3 (P < 0.05; Table 2, Figure 3E, I and M). By contrast, no significant differences in marker expression were detected in normal gastric mucosal organoids before and after taurine treatment (P > 0.05), suggesting that taurine selectively modulates the GIM phenotype.

Table 2 Summary of molecular marker expression changes in patient-derived gastric intestinal metaplasia organoids after taurine intervention.

Patient	Marker	Normal untreated	Normal + taurine (vs untreated normal)	GIM untreated (vs untreated normal)	GIM + taurine (vs untreated GIM)	P value (GIM + taurine vs untreated GIM)	Detection method
All (1-3)	CDX2	Baseline	-	Upregulated (significant)	Downregulated (significant)	< 0.05	qPCR, WB
All (1-3)	MUC2	Baseline	-	Upregulated (significant)	Downregulated (significant)	< 0.05	qPCR
All (1-3)	TFF3	Baseline	-	Upregulated (significant)	Downregulated (significant)	< 0.05	qPCR, WB
1 & 3	MUC5AC	Baseline	-	Downregulated (significant)	Upregulated (significant)	< 0.05	qPCR
2	MUC5AC	Baseline	-	Downregulated (significant)	Upregulated (nonsignificant)	> 0.05	qPCR

CDX2: Caudal type homeobox 2; GIM: Gastric intestinal metaplasia; IHC: Immunohistochemistry; MUC2: Mucin 2; MUC5AC: Mucin 5AC; qPCR: Quantitative PCR; TFF3: Trefoil factor family 3; WB: Western blot.

Collectively, these findings demonstrate that taurine attenuates GIM characteristics in human-derived organoids by downregulating the expression of intestinal epithelial-specific markers and increasing the expression of gastric mucosal-specific markers, thereby providing human-relevant in vitro evidence to support its potential clinical application in GIM intervention.

DISCUSSION

This study demonstrates, for the first time, the robust efficacy of taurine in attenuating GIM via complementary in vivo and human-derived ex vivo models. Consistent findings from both Atp4a^-/- murine models and patient-derived GIM organoids provide compelling evidence that taurine supplementation reverses key pathological features of GIM by restoring gastric epithelial identity and suppressing intestinal programming. These results identify taurine as a promising candidate for the chemoprevention of GC.

At the animal level, we confirmed that 12-week-old Atp4a^-/- mice spontaneously develop typical GIM features, including disrupted gastric mucosal architecture, vacuolar dilation of glandular ducts, and the coexistence of neutral and acidic mucins. These findings validate Atp4a^-/- mice as a stable and reliable model for mechanistic studies and drug screening. Taurine intervention markedly improved gastric mucosal morphology, downregulated the expression of intestinal epithelial-specific markers (CDX2, MUC2, TFF3), and upregulated the expression of the gastric mucosal-specific marker MUC5AC. This dual regulatory mechanism—suppressing intestinal markers while promoting gastric markers—suggests that taurine acts not only as a cytoprotective agent but also as an active reprogrammer of the metaplastic epithelium toward a normal gastric phenotype.

The replication of these effects in patient-derived GIM organoids greatly strengthens the translational value of our findings. Organoids preserve the genetic and phenotypic landscape of the original lesion, making them excellent platforms for predicting therapeutic response. The finding that taurine elicited the same regulatory pattern (decreased CDX2/MUC2/TFF3 and increased MUC5AC) in this human system validates the murine data and indicates a conserved mechanism across species. This effectively rules out species-specific artifacts and underscores taurine’s potential as a clinically applicable intervention.

The molecular mechanisms underlying the effects of taurine merit further investigation. Its well-established antioxidant properties may counteract oxidative stress, a driver of GIM initiation and progression[38,39]. As a bile acid conjugate, taurine may also neutralize the damaging effects of bile reflux, a recognized trigger of metaplasia[40-43]. In addition, taurine can modulate signaling pathways central to metaplastic transformation, such as the nuclear factor kappa B, signal transducer and activator of transcription 3, or Wnt/β-catenin pathways, thereby promoting a favorable gastric microenvironment[44,45]. Future studies should aim to delineate the direct molecular targets and pathways by which taurine exerts these effects. This study utilized immunohistochemistry with semiquantitative scoring, which provided optimal assessment of protein expression differences across gastric tissue architectures. While techniques such as immunofluorescence could offer enhanced subcellular resolution, the current methodology effectively captured the distinct expression patterns necessary for group comparisons. Future investigations may incorporate higher-resolution approaches to further explore the subcellular distribution of these markers in GIM.

Despite these encouraging results, limitations remain. While we observed a clear shift in the expression of differentiation markers, the upstream signaling cascades modulated by taurine require elucidation. The optimal dose, treatment duration, and long-term efficacy in humans remain to be established through clinical trials. Furthermore, it is essential to determine whether the protective effects of taurine are consistent across all GIM subtypes or restricted to specific variants.

CONCLUSION

Our study provides strong preclinical evidence supporting taurine as a therapeutic candidate for GIM. Using both a genetic murine model and patient-derived organoids, we demonstrated that taurine markedly attenuated GIM features and restored gastric epithelial identity. Owing to its well-documented safety, affordability, and broad availability, taurine has emerged as a practical and attractive option for clinical translation, either as a dietary supplement or a pharmaceutical intervention to halt the progression of gastric carcinogenesis. These findings establish a solid foundation for future randomized controlled trials to validate taurine as a chemopreventive strategy in patients with this precancerous condition.