Gut Dysbiosis in Patients with Anorexia Nervosa

Abstract

Anorexia nervosa (AN) is a psychological illness with devastating physical consequences; however, its pathophysiological mechanism remains unclear. Because numerous reports have indicated the importance of gut microbiota in the regulation of weight gain, it is reasonable to speculate that AN patients might have a microbial imbalance, i.e. dysbiosis, in their gut. In this study, we compared the fecal microbiota of female patients with AN (n = 25), including restrictive (ANR, n = 14) and binge-eating (ANBP, n = 11) subtypes, with those of age-matched healthy female controls (n = 21) using the Yakult Intestinal Flora-SCAN based on 16S or 23S rRNA–targeted RT–quantitative PCR technology. AN patients had significantly lower amounts of total bacteria and obligate anaerobes including those from the Clostridium coccoides group, Clostridium leptum subgroup, and Bacteroides fragilis group than the age-matched healthy women. Lower numbers of Streptococcus were also found in the AN group than in the control group. In the analysis based on AN subtypes, the counts of the Bacteroides fragilis group in the ANR and ANBP groups and the counts of the Clostridium coccoides group in the ANR group were significantly lower than those in the control group. The detection rate of the Lactobacillus plantarum subgroup was significantly lower in the AN group than in the control group. The AN group had significantly lower acetic and propionic acid concentrations in the feces than the control group. Moreover, the subtype analysis showed that the fecal concentrations of acetic acid were lower in the ANR group than in the control group. Principal component analysis confirmed a clear difference in the bacterial components between the AN patients and healthy women. Collectively, these results clearly indicate the existence of dysbiosis in the gut of AN patients.

Gut microbiota, metabolism and psychopathology: A critical review and novel perspectives

“…Dysbiosis in the gut microbiota is thought to be an important environmental factor involved in the pathophysiology of AN [76]. Significant differences in total number of bacteria and relative abundances of bacterial taxa were found in multiple small studies.…”

“…Patients harboring an increased concentration of M. smitthii, showed a negative correlation (r¼ À0.20) with body mass index. Morita et al [76] compared the fecal microbiota composition of AN patients (n ¼ 25) with healthy controls. Patients with AN had significantly lower amounts anaerobes (C. coccoides group, B. fragilis, C. leptum and Streptococcus) and total bacteria.…”

The Microbiota, the Gut and the Brain in Eating and Alcohol Use Disorders: A ‘Ménage à Trois’?

“…Indeed, Anorexia Nervosa (AN) patients have significantly lower amounts of total intestinal bacteria and higher prevalence of specific bacterial strains, which may reflect altered metabolic capacity resulting from the disorder (Armougom et al, 2009;Morita et al, 2015;Bulik, 2016;Carr et al, 2016;Mack et al, 2016). Gut bacteria may play a role in cravings for specific foods or induce dysphoria to motivate the ingestion of foods (Alcock et al, 2014).…”

Weight gain in anorexia nervosa does not ameliorate the faecal microbiota, branched chain fatty acid profiles and gastrointestinal complaints

“…Million et al 12. and Morita et al 13. analysed a selected range of gut microorganisms in 9 AN, 15 AN and 25 AN patients, respectively.…”