Altered host-gut microbes symbiosis in severely malnourished anorexia nervosa (AN) patients undergoing enteral nutrition: An explicative factor of functional intestinal disorders?

Intestinal microbiota and Anorexia Nervosa

“…As already discussed above, the observed increase in M. smithii in the intestine of anorectic patients may for instance contribute to constipation through the production of methane by this Archaea, which slows down intestinal motility [36]. The putative role of the microbiota in functional gastrointestinal disorders has recently been highlighted by a study on severely malnourished anorectic patients, which identified correlations between changes in specific bacterial genera with severity of functional gastrointestinal disorders [46]. Characterization of the involvement of gut microbes in these functional intestinal disorders is essential as it would help to identify new putative therapeutic targets in order to decrease these disorders and improve quality of life and treatment efficiency of AN.…”

“…Measurement of bacterial abundance and alpha diversity (i.e. bacterial species richness in one individual) of anorectic patients' microbiota are diverging between studies: some studies observed decreases while other studies showed no alteration of these parameters compared to healthy individuals [40e43, 45,46]. It is thus difficult to draw definitive conclusions on the modification of these parameters during AN.…”

Host Starvation and Female Sex Influence Enterobacterial ClpB Production: A Possible Link to the Etiology of Eating Disorders

“…For instance, we previously found that ClpB production is enriched in the protein fractions of E. coli from the stationary growth phase induced by regular nutrient provision, which activates intestinal and brain satiety pathways [16]. Moreover, ED patients display elevated plasma levels of enterobacterial ClpB [27], while an increased prevalence of Enterobacteriaceae was reported in AN patients [28][29][30]. Since ClpB-expressing E. coli display anorexigenic and body weight-lowering properties that are dependent on ClpB's presence [5], it is possible that an increased prevalence of ClpB-producing bacteria may underlie the enhanced anorexigenic effect of gut bacteria in ED patients.…”

Backstage of Eating Disorder—About the Biological Mechanisms behind the Symptoms of Anorexia Nervosa

“…A reduction in microbial diversity was related to impaired immune defense and limited ability to obtain calories from food [123]. Inconsistent results (Table 3) are observed between studies regarding the Firmicutes/Bacteroidetes ratio or the identity of altered levels of bacterial taxa in these patients [122,[124][125][126][127][128][129][130][131][132], either. According to Fava et al an increased level of Bacteroidetes were linked to weight loss, which is, at least partly, characteristic for AN patients [133].…”