Changes in Gut Microbiota Composition after Bariatric Surgery: a New Balance to Decode

Abstract

Background Recently, the link between obesity and gut microbiota has become a focus for research. This study shed some light on the modification of postoperative gut microbial composition after bariatric surgery. Methods A prospective longitudinal study on healthy lean subjects and patients who underwent bariatric surgery (Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy) was carried out. Anthropometric and metabolic data, smoking, food preferences data, and stool samples were collected from lean subjects and from obese patients before and 3 and 6 months after surgery (T0, T3, and T6, respectively). Results We collected stool samples from 25 obese patients before surgery and 3 and 6 months thereafter and from 25 normal weight patients. After Roux-en-Y gastric bypass, Yokenella regensburgei (p < 0.05), Fusobacterium varium (p < 0.05), Veillonella dispar/atypica (p < 0.05), and Streptococcus australis/gordonii (p < 0.05) were transiently identified in the gut at T3. Roux-en-Y gastric bypass patients had a permanent increase in Akkermansia muciniphila (p < 0.05), which is associated with healthy metabolism, both at T3 and T6. There were no significant changes in gut microbiota in laparoscopic sleeve gastrectomy patients. Conclusions In our study, Roux-en-Y gastric bypass induced major microbial differences and greater weight loss compared with laparoscopic sleeve gastrectomy. Analyzing the microbiota composition, a proliferation of potential pathogens and the onset of beneficial bacteria was observed. The effects of these bacteria on human health are still far from clear. Understanding the mechanisms of action of these bacteria could be the keystone in developing new therapeutic strategies for obesity.

Microbiome, bile acids, and obesity: How microbially modified metabolites shape anti‐tumor immunity

“…A significant and lasting increase in A muciniphila has also been observed in human patients following Roux-En-Y, but not in VSG, suggesting diversion of BAs conferred by BD or Roux-En-Y surgery may be necessary for alteration in the distal gut microbiome. 56 Dietary interventions also modulate the gut microbiome. 57 Consistent with observations in bariatric surgery and obesity, high-fat diet-induced obesity suppresses A muciniphila abundance in animal models.…”

Exercise-Driven Increase in Gut Microbial Hydrogen Production as a Possible Factor of Metabolic Health

“…In addition, exercise-induced alterations of the gut microbiota appear dependent on obesity status (Allen et al, 2018 ), with exercise increased fecal metabolites in lean, but not obese, participants. These findings implies that the degree of obesity and leanness has a contributory effect on gut microbiota, and this was seen also in subjects who had undergone bariatric surgery (Palmisano et al, 2020 ). In addition, an increased production of hydrogen gas by gut bacteria could also have adverse effects.…”

The Potential Gut Microbiota-Mediated Treatment Options for Liver Cancer

“…Combined (synbiotic) prebiotic B. infantis and probiotic milk oligosaccharide treatment reverses Western diet (WD)-induced NASH in FXR knockout mice ( 72 ). Moreover, bariatric surgery, such as Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy, can induce the shift of gut microbiota to reduce obesity and weight loss ( 73 ), showing a promise in NAFLD and NASH ( 74 ). Thus, it may be a potent treatment option for early stage of NASH-HCC patients.…”