Bacteroides uniformis CECT 7771 Ameliorates Metabolic and Immunological Dysfunction in Mice with High-Fat-Diet Induced Obesity

Abstract

BackgroundAssociations have been made between obesity and reduced intestinal numbers of members of the phylum Bacteroidetes, but there is no direct evidence of the role these bacteria play in obesity. Herein, the effects of Bacteroides uniformis CECT 7771 on obesity-related metabolic and immune alterations have been evaluated.Methods and FindingsAdult (6–8 week) male wild-type C57BL-6 mice were fed a standard diet or a high-fat-diet HFD to induce obesity, supplemented or not with B. uniformis CECT 7771 for seven weeks. Animal weight was monitored and histologic, biochemical, immunocompetent cell functions, and features of the faecal microbiota were analysed after intervention. The oral administration of B. uniformis CECT 7771 reduced body weight gain, liver steatosis and liver cholesterol and triglyceride concentrations and increased small adipocyte numbers in HFD-fed mice. The strain also reduced serum cholesterol, triglyceride, glucose, insulin and leptin levels, and improved oral tolerance to glucose in HFD fed mice. The bacterial strain also reduced dietary fat absorption, as indicated by the reduced number of fat micelles detected in enterocytes. Moreover, B. uniformis CECT 7771 improved immune defence mechanisms, impaired in obesity. HFD-induced obesity led to a decrease in TNF-α production by peritoneal macrophages stimulated with LPS, conversely, the administration of B. uniformis CECT 7771 increased TNF-α production and phagocytosis. Administering this strain also increased TNF-α production by dendritic cells (DCs) in response to LPS stimulation, which was significantly reduced by HFD. B. uniformis CECT 7771 also restored the capacity of DCs to induce a T-cell proliferation response, which was impaired in obese mice. HFD induced marked changes in gut microbiota composition, which were partially restored by the intervention.ConclusionsAltogether, the findings indicate that administration of B. uniformis CECT 7771 ameliorates HFD-induced metabolic and immune dysfunction associated with intestinal dysbiosis in obese mice.

Mannose Alters Gut Microbiome, Prevents Diet-Induced Obesity, and Improves Host Metabolism

“…This shift has significant effects on GH and sugar metabolism in these taxonomic groups. Species such as B. acidifaciens and B. uniformis ameliorate obesity by immunomodulation and improved host metabolism (Gauffin Cano et al, 2012; Yang et al, 2017). However, the mechanism for these effects is unknown.…”

The gut microbiota: a key regulator of metabolic diseases

“…Oral administration of the B. uniformis CECT 7771 strain ameliorated HFD-induced metabolic dysfunction in obese mice (62). Our group has recently reported that HFD-fed mice given B. acidifaciens for 10 weeks gained less fat mass and body weight than those given PBS alone (45).…”

Microbiome and metabolic disease: revisiting the bacterial phylum Bacteroidetes

“…Dosing of conventionally raised mice with cultures of B. uniformis [51], B. acidifaciens [52], or P. copri [29] resulted in improved glucose tolerance and insulin sensitivity compared to dosing with heat-killed cultures as controls. Authors of these studies speculate that microbial metabolites could be effectors of improved metabolism.…”