Published online Feb 16, 2015. doi: 10.12998/wjcc.v3.i2.156
Peer-review started: July 28, 2014
First decision: September 16, 2014
Revised: October 9, 2014
Accepted: October 28, 2014
Article in press: October 29, 2014
Published online: February 16, 2015
Processing time: 192 Days and 23.6 Hours
The aim of the present systematic review is to summarize the existing knowledge about the human microbiota in the elderly and the effects of probiotics in elderly population. The elderly subjects, compared to adult population, show a reduction in the diversity of the microbiota, characterized by a large interindividual variability, with lower numbers of Firmicutes, Bifidobacteria, Clostridium cluster XIV, Faecalibacterium Prausnitzii, Blautia coccoides-Eubacterium rectal and higher presence of Enterobacteriaceae and Bacteroidetes. These differences of the intestinal microbiota of the elderly may not necessarily be caused by aging, but they could be associated with the decline of the general state of health with malnutrition and with increased need for medication, such as antibiotics and nonsteroidal anti-inflammatory drugs, situations that occur frequently in the elderly. Differences have been demonstrated in the composition of the microbiota between healthy elderly subjects and hospitalized or institutionalized elderly subjects. These findings which further indicates that the living conditions, health status, nutrition and drugs have a significant effect on the composition of the microbiota. According to the available knowledge, the use of probiotics is safe and could represent an useful intervention to prevent or treat antibiotic-associated diarrhea, in addition to reducing the severity of symptoms, other than to help the management of constipation.
Core tip: The intestinal microbiota of elderly manifested a reduction in the diversity, characterized by a large interindividual variability, with lower numbers of Firmicutes, Bifidobacteria, Clostridium cluster XIV, Faecalibacterium Prausnitzii, Blautia coccoides-Eubacterium rectal and higher in Enterobacteriaceae and Bacteroidetes. These derangements may not necessarily aging-correlated, but they can be consequent to the decline of general state of health, malnutrition and increased use of drugs. As regards probiotics, the main double-blind studies in the elderly have shown that use is safe and could represent an interesting support to reduced frequency and/or duration of antibiotic-associated diarrhea, other than to help for constipation.