Mohamed Tausif R. Siddiqui, MD
This is a very interesting study by Mathur and her team that explores small intestinal microbiome from the perspective of the normal aging process. With their large-scale REIMAGINE (Revealing the Entire Intestinal Microbiota and its Associations with the Genetic, Immunologic and Neuroendocrine Ecosystem) initiative, the authors have previously reported the significant differences between fecal and small intestinal microbiome.
The investigating team collected duodenal aspirates from 251 patients aged 18 to 80 years and analyzed age-specific changes that occur in the small intestinal microbiome. There was decreased alpha microbial diversity with advancing age and an increase in facultative and obligate anaerobes. This study also noted that, in addition to chronological age, a specific pattern of changes in the relative abundance of microbiome occurred in response to the number of medications and comorbidities, and there was an overall shift towards a proinflammatory state that occurred with these changes.
This study is an important addition to our existing knowledge base of intestinal microbiome. Age-related changes in microbiome may have an important implication for certain conditions, such as Alzheimer’s disease, but this study expands further into the spectrum of gastrointestinal disease. Understanding these age-related changes in the gut microbiome could also help us characterize disorders, such as irritable bowel syndrome and small intestinal bacterial overgrowth, which affect relatively younger populations. Small intestinal microbiome is not only different from fecal microbiome, but substantial differences exist between luminal and mucosal microbiota. This could be of particular importance in conditions of bacterial overgrowth recurrence, in which the mucosal microbiome — in close association with the human immune system — holds these distinct imprints of gut luminal microbiome profiles. Further exploration of these key issues could help us develop therapy to reprogram the microbiota for a curative treatment approach.
Mohamed Tausif R. Siddiqui, MD
Fellow, Department of Gastroenterology, Hepatology and Nutrition
Digestive Disease & Surgery Institute
Cleveland Clinic
Disclosures: Siddiqui reports no relevant disclosures.