Compensatory intestinal antibody response against pro-inflammatory microbiota after bariatric surgery

Abstract

Obesity and type 2 diabetes (T2D) are growing burdens for individuals and the health-care system. Bariatric surgery is an efficient, but drastic treatment to reduce body weight, normalize glucose values, and reduce low-grade inflammation. The gut microbiome, which is in part controlled by intestinal antibodies, such as IgA, is involved in the development of both conditions. Knowledge of the effect of bariatric surgery on systemic and intestinal antibody response is limited. Here, we determined the fecal antibody and gut microbiome response in 40 T2D and non-diabetic (ND) obese individuals that underwent bariatric surgery (N = 40). Body weight, fasting glucose concentrations and inflammatory parameters decreased after bariatric surgery, whereas pro-inflammatory bacterial species such as lipopolysaccharide (LPS), and flagellin increased in the feces. Simultaneously, concentrations of LPS- and flagellin-specific intestinal IgA levels increased with the majority of pro-inflammatory bacteria coated with IgA after surgery. Finally, serum antibodies decreased in both groups, along with a lower inflammatory tone. We conclude that intestinal rearrangement by bariatric surgery leads to expansion of typical pro-inflammatory bacteria, which may be compensated by an improved antibody response. Although further evidence and mechanistic insights are needed, we postulate that this apparent compensatory antibody response might help to reduce systemic inflammation by neutralizing intestinal immunogenic components and thereby enhance intestinal barrier function after bariatric surgery.

The role and mechanisms of gut microbiota in diabetic nephropathy, diabetic retinopathy and cardiovascular diseases

“…Recently studies showed that gut microbiota dysbiosis can contribute to eye diseases ( Rowan and Taylor, 2018 ; Janowitz et al, 2019 ) proposing the “gut-retina axis.” Diabetic patients with delayed gastric emptying had a higher risk of retinopathy, while bariatric surgery reduced the incidence of DR ( Parkman et al, 2019 ; Singh et al, 2021 ). Bariatric surgery can change microbiota structure and enhance intestinal barrier function facilitating weight loss and improving glycemic control, which is a key factor in DR ( Koutoukidis et al, 2022 ; Scheithauer et al, 2022 ). Recently, a direct relationship between gut microbiota and DR was shown.…”

IgA in human health and diseases: Potential regulator of commensal microbiota

“…Similarly, IgA binding to pathogenic E. coli is increased in the feces of patients with spondyloarthritis ( 40 ). IgA-coated bacteria are also altered in multiple sclerosis ( 41 , 42 ), kwashiorkor ( 43 ), obesity after bariatric surgery ( 44 ), and certain types of cancer ( 45 ). These results suggest that IgA may have the ability to bind to and control potentially harmful commensal bacteria that are involved in human pathogenesis.…”

Achieving pan-microbiome biological insights via the dbBact knowledge base

“…Detecting intra-host similarities: dbBact can identify similarities within hosts. (i) For example, Scheithauer et al (56) profiled the bacteria detected in the IgA-positive and IgA-negative fractions of fecal samples. dbBact-based analysis shows that the IgA-positive fraction is enriched in oral related terms, indicating a possible contribution of oral IgA to bacterial antibody coating (Figure S8).…”