Published online Feb 28, 2022. doi: 10.3748/wjg.v28.i8.811
Peer-review started: October 1, 2021
First decision: November 7, 2021
Revised: November 19, 2021
Accepted: January 14, 2022
Article in press: January 14, 2022
Published online: February 28, 2022
Processing time: 146 Days and 9.1 Hours
Nodular lymphoid hyperplasia (NLH) in the small intestine is a rare benign lesion characterized by multiple small nodules on the intestinal surface. NLH is linked to the immune system, and it may result from accumulation of plasma-cell precursors due to a maturational defect during the development of B lymphocytes. The intestinal microbiome plays an essential role in the immune system. However, whether the gut flora plays a role in NLH is unclear.
To explore the correlation between intestinal flora and terminal ileal NLH and predict the metabolic pathways that are involved in terminal ileal NLH.
To investigate the characteristics of the mucosal microbiata in patients with terminal ileal NLH for seeking related bacteria genera and bringing a new idea for related mechanisms.
A total of 30 patients who underwent a colonoscopy were recruited for this study. A total of 15 Patients with terminal ileal NLH were assigned to the test group, while 15 healthy volunteers were assigned to the control group after undergoing a routine physical examination. We collected mucosal biopsy samples that were obtained via colonoscopy from both groups. We subsequently performed 16S-rRNA gene amplicon sequencing of these samples, and the results were evaluated using alpha diversity, beta diversity and microbial composition analyses. The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States was used to predict the metabolic pathways and orthologous groups according to the Kyoto Encyclopedia of Genes and Genomes database.
The terminal ileal NLH group showed an increased alpha diversity.The overall intestinal microbiota in the NLH group was significantly different from that of the control group. The relative abundance of phylum Bacteroidetes was significantly lower in the NLH group, while that of Patescibacteria and Campilobacterota was significantly higher. The abundance of the genus Bacteroides was significantly lower in the test group. Conversely, the relative abundances of Haemophilus, Streptococcus, Pseudomonas, Actinomyces, TM7X, Fusobacterium nucleatum, Parvimonas, Granulicatella, Helicobacter, and the [Eubacterium] nodatum group were significantly higher in the test group. Metabolic pathways such as Peptidoglycan biosynthesis and Aminoacyl tRNA biosynthesis were both increased in the test group.
Maintaining the microbial balance and supplementing targeted protective bacteria could improve symptoms and potentially reduce the risk of lymphoma transformation in patients with terminal ileal NLH.
Further research on the related mechanisms was needed to be performed in future. Further studies using animal testing in vivo and in vitro cellular experiments can be developed once our findings are verified in larger populations.