Gut microbiota predicts body fat change following a low-energy diet: a PREVIEW intervention study.

BACKGROUND: Low-energy diets (LEDs) comprise commercially formulated food products that provide between 800 and 1200 kcal/day (3.3-5 MJ/day) to aid body weight loss. Recent small-scale studies suggest that LEDs are associated with marked changes in the gut microbiota that may modify the effect of the LED on host metabolism and weight loss. We investigated how the gut microbiota changed during 8 weeks of total meal replacement LED and determined their associations with host response in a sub-analysis of 211 overweight adults with pre-diabetes participating in the large multicentre PREVIEW (PREVention of diabetes through lifestyle intervention and population studies In Europe and around the World) clinical trial. METHODS: Microbial community composition was analysed by Illumina sequencing of the hypervariable V3-V4 regions of the 16S ribosomal RNA (rRNA) gene. Butyrate production capacity was estimated by qPCR targeting the butyryl-CoA:acetate CoA-transferase gene. Bioinformatics and statistical analyses, such as comparison of alpha and beta diversity measures, correlative and differential abundances analysis, were undertaken on the 16S rRNA gene sequences of 211 paired (pre- and post-LED) samples as well as their integration with the clinical, biomedical and dietary datasets for predictive modelling. RESULTS: The overall composition of the gut microbiota changed markedly and consistently from pre- to post-LED (P = 0.001), along with increased richness and diversity (both P < 0.001). Following the intervention, the relative abundance of several genera previously associated with metabolic improvements (e.g., Akkermansia and Christensenellaceae R-7 group) was significantly increased (P < 0.001), while flagellated Pseudobutyrivibrio, acetogenic Blautia and Bifidobacterium spp. were decreased (all P < 0.001). Butyrate production capacity was reduced (P < 0.001). The changes in microbiota composition and predicted functions were significantly associated with body weight loss (P < 0.05). Baseline gut microbiota features were able to explain ~25% of variation in total body fat change (post-pre-LED). CONCLUSIONS: The gut microbiota and individual taxa were significantly influenced by the LED intervention and correlated with changes in total body fat and body weight in individuals with overweight and pre-diabetes. Despite inter-individual variation, the baseline gut microbiota was a strong predictor of total body fat change during the energy restriction period. TRIAL REGISTRATION: The PREVIEW trial was prospectively registered at ClinicalTrials.gov ( NCT01777893 ) on January 29, 2013.

The salivary scavenger and agglutinin in early life: diverse roles in amniotic fluid and in the infant intestine.

The salivary scavenger and agglutinin (SALSA), also known as gp340 and dmbt1, is an antimicrobial and inflammation-regulating molecule located at the mucosal surfaces. The present study revealed that SALSA was present in the amniotic fluid (AF) and exceptionally enriched in both meconium and feces of infants. Based on immunological and mass spectrometric analysis, SALSA was estimated to constitute up to 4-10% of the total protein amount in meconium, making it one of the most abundant proteins. SALSA proteins in the AF and intestinal samples were polymorphic and exhibited varying polypeptide compositions. In particular, a different abundance of peptides corresponding to functionally important structures was found in the AF and intestinal SALSA. The AF form of SALSA had a more intact structure and contained peptides from the zona pellucida domain, which is involved in cell differentiation and oligomerization. In contrast, the intestinal SALSA was more enriched with the scavenger receptor cysteine-rich domains. The AF, but not the meconium SALSA, bound to Streptococcus pyogenes, S. agalactiae, S. gordonii, and Escherichia coli. Furthermore, differential binding was observed also to known endogenous ligands C1q, mannose-binding lectin, and secretory IgA. Our results have thus identified mucosal body compartments, where SALSA is particularly abundant, and suggest that SALSA exhibits varying functions in the different mucosal locations. The high levels of SALSA in AF and the infant intestine suggest a robust and important function for SALSA during the fetal development and in the mucosal innate immune defense of infants.