Gastric bypass surgery {51111200}

Shared Reference Notes

• [1.1] [#Diabetes Type 2] 
  - there is a negative association between specific species such as B. adolescentis, B. bifidum, B. pseudocatenulatum, B. longum, B. dentium and disease in patients treated with #Metformin or after undergoing gastric bypass surgery
• [1.2] 
  - Higher #Butyrate- and #Propionate-to-#Acetate ratios after the surgery compared to baseline indicates a shift in microbial metabolism from #Acetate production to #Butyrate and #Propionate production. - #Butyrate and #Propionate, which are known to induce satiety in animals and humans, were in greater concentrations in post-RYGB patients compared to nonsurgical controls.
• - #Lactococcus, #Streptococcus, and #Granulicatella are #Lactate-producing microorganisms, whereas #Dorea and #Blautia are #Lactate oxidizers
• [#Branched-chain fatty acids] - RYGB surgery > the fecal concentrations of two BCFAs—#Isobutyrate and #Isovalerate—increased after surgery
• [#Secondary bile acids] - Roux-en-Y gastric bypass surgery (RYGB) > The changes in the fecal microbiome were linked to increased concentrations of #Branched-chain fatty acids and an overall decrease in secondary bile acid concentrations. - RYGB surgery also increased bile acid concentrations in plasma
• [#Diabetes Type 2] - An increase in #Propionate and #Bile Acids after RYGB was associated with an increase in hormone peptide tyrosine tyrosine (PYY) in humans and, hence, resolution of diabetes.
• - One of the microbial staples of RYGB surgery is enrichment of phylotypes from #Gammaproteobacteria
• - RYGB surgery > an increase in the abundance of Proteobacteria phylotypes Rothia, Aggregatibacter, Granulicatella, Citrobacter, Janthinobacterium, and Klebsiella. - Akkermansia from Verrucomicrobia and Adlercruetzia and Rothia from Actinobacteria also were in greater abundance after RYGB.
• - Streptococcus, Enterococcus, Lactococcus, Veillonella, and Granulicatella—were enriched, Ruminococcus, Blautia, and Roseburia were depleted after RYGB surgery.
• - changes in the microbiome occurred quickly after the surgery (within 6 months) and persisted in the long term (>60 months).
• - Six genus-level phylotypes were significantly enriched in the mucosa after RYGB surgery: Granulicatella, Lactococcus, Streptococcus, Blautia, Dorea, and Akkermansia.
• - alterations in the gastrointestinal mucosa after RYGB may contribute to an increase in mucin-degrading, lactate-producing, and lactate-oxidizing microorganisms.
• - concentrations of #Xylose also increased after RYGB
• [1.3] 
  - Roux-en-Y gastric bypass (RYGB) resulted in clear alteration in composition of gut fungal and bacterial microbiota. - Before surgery, patients had higher levels of #Firmicutes and #Actinobacteria and lower levels of #Verrucomicrobia - #Faecalibacterium and #Bifidobacterium showed a decrease after surgery and aerotolerant #Streptococcus was increased postoperatively. - The relative abundance of #Proteobacteria was increased after surgery. - Changes in fungal microbiota composition included decreases in #Candida and #Saccharomyces and increases in #Pichia. - levels of #Verrucomicrobia and #Proteobacteria increased after the surgery procedure - Bifidobacteriaceae abundance decreased, whereas Streptococcaceae and Enterobacteriaceae increased after surgery. - RYGB led to increased #Firmicutes and #Actinobacteria phyla but decreased #Bacteroidetes phylum

References Notes