Processed Animal Proteins from Insect and Poultry By-Products in a Fish Meal-Free Diet for Rainbow Trout: Impact on Intestinal Microbiota and Inflammatory Markers

Sustainability of aquaculture is tied to the origin of feed ingredients. In search of sustainable fish meal-free formulations for rainbow trout, we evaluated the effect of Hermetia illucens meal (H) and poultry by-product meal (P), singly (10, 30, and 60% of either H or P) or in combination (10% H + 50% P, H10P50), as partial replacement of vegetable protein (VM) on gut microbiota (GM), inflammatory, and immune biomarkers. Fish fed the mixture H10P50 had the best growth performance. H, P, and especially the combination H10P50 partially restored \u3b1-diversity that was negatively affected by VM. Diets did not differ in the Firmicutes:Proteobacteria ratio, although the relative abundance of Gammaproteobacteria was reduced in H and was higher in P and in the fishmeal control. H had higher relative abundance of chitin-degrading Actinomyces and Bacillus, Dorea, and Enterococcus. Actinomyces was also higher in H feed, suggesting feed-chain microbiome transmission. P increased the relative abundance of protein degraders Paeniclostridium and Bacteroidales. IL-1\u3b2, IL-10, TGF-\u3b2, COX-2, and TCR-\u3b2 gene expression in the midgut and head kidney and plasma lipopolysaccharide (LPS) revealed that the diets did not compromise the gut barrier function or induce inflammation. H, P, and H10P50 therefore appear valid protein sources in fishmeal-free aquafeeds

Measuring the effect of Mankai® (Wolffia globosa) on the gut microbiota and its metabolic output using an in vitro colon model

10openInternationalInternational coauthor/editorMankai® is a cultivated strain of Wolffia globosa an aquatic plant of the family Lemnaceae commonly known as Duckweeds. Recent studies suggest that consumption of a Mankai® enriched diet may provide positive health effects by decreasing body weight and improving glucose homeostasis and plasma lipid profiles. However, the effects of Mankai® alone on the composition and metabolic output of the human gut microbiota has not been fully investigated. Here, Mankai® was digested and fermented in vitro using a batch culture model of the proximal colon. Inulin and cellulose were used as readily and poorly fermentable control fibers respectively. Mankai® significantly stimulated the production of phenolic metabolites and short chain fatty acids by the gut microbiota (p<0.05). Three major microbial metabolites, 3-4-hydroxyphenyl propionic acid, 3-3-hydroxyphenyl propanoic acid and protocatechuic acid were significantly increased after 24 h fermentation. Moreover, Mankai® treatment lowered the overall microbial diversity (p<0.05), in line with a selective microbiome modulation.openDiotallevi, Camilla; Gaudioso, Giulia; Fava, Francesca; Angeli, Andrea; Lotti, Cesare; Vrhovsek, Urska; Rinott, Ehud; Shai, Iris; Gobbetti, Marco; Tuohy, KieranDiotallevi, C.; Gaudioso, G.; Fava, F.; Angeli, A.; Lotti, C.; Vrhovsek, U.; Rinott, E.; Shai, I.; Gobbetti, M.; Tuohy, K

Salivary microbial profiles associate with responsiveness to warning oral sensations and dietary intakes

Oral microbiota-host interactions are gaining recognition as potential factors contributing to interindividual variations in taste perception. However, whether such possible links imply specific bacterial co-occurrence networks remains unknown. To address this issue, we used 16&nbsp;s rRNA gene sequencing to profile the salivary microbiota of 100 healthy individuals (52 % women; 18-30 y/o), who provided hedonic and psychophysical responses to 5 liquid and 5 solid commercially-available foods, each chosen to elicit a target sensation (sweet, sour, bitter, salty, pungent). The same cohort also completed several psychometric measures and a 4-day food diary. Unsupervised data-driven clustering of genus-level Aitchison distances supported the existence of two salivary microbial profiles (CL-1, CL-2). While CL-1 (n&nbsp;=&nbsp;57; 49.1 % women) exhibited higher α-diversity metrics and was enriched in microbial genera assigned to the class Clostridia (e.g., Lachnospiraceae_[G-3]), CL-2 (n&nbsp;=&nbsp;43; 55.8 % women) harbored greater amounts of taxa with potential cariogenic effects (e.g., genus Lactobacillus) and significantly lower abundances of inferred MetaCyc pathways related to the metabolic fate of acetate. Intriguingly, CL-2 showed enhanced responsiveness to warning oral sensations (bitter, sour, astringent) and a higher propensity to crave sweet foods or engage in prosocial behaviors. Further, the same cluster reported habitually consuming more simple carbohydrates and fewer beneficial nutrients (vegetable proteins, monounsaturated fatty acids). In summary, while the mediating role of participants' baseline diet on findings can not be definitively excluded, this work provides evidence suggesting that microbe-microbe and microbe-taste interactions may exert an influence on dietary habits and motivates further research to uncover a potential "core" taste-related salivary microbiota

Variations in oral responsiveness associate with specific signatures in the gut microbiota and modulate dietary habits

Mounting evidence suggests that ingestive behaviors may also be affected by putative interplays between taste and gut microbiota. As yet empirically unproven, we here tested the hypothesis that variations in sensory perception in foods can mirror gut microbial ecology and shape individual dietary habits. One hundred healthy participants (52 % women, 18–30 y/o) remotely attended a 7-day (D) lasting protocol, and evaluated bitterness (D1) of 6-n-propylthiouracil (PROP) plus liking (D2) and intensity of sensations (D4) evoked by 5 liquid and 5 solid foods, each selected to elicit a target sensation (sweet, sour, bitter, salty, pungent). Furthermore, volunteers completed a battery of psychological questionnaires (D3), a 4-day dietary record (D1–D7), and provided one stool sample for fecal microbiota profiling by 16S rRNA gene sequencing (D4). Using a data-driven segmentation approach based on intensity scores, we identified two distinct profiles that were hypo- (CL-1, n = 36, 55.5 % women) and hyperresponsive (CL-2, n = 64, 50 % women) to oral stimulations. Moreover, CL-2 showed higher percentages of PROP Medium Tasters and pronounced pleasure-oriented attitudes. Interestingly, CL-1 exhibited higher α-diversity metrics and was enriched in 11 beneficial gut microbes (e.g., genus Eubacterium_xylanophilum_group), while two pro-inflammatory microbial genera (Ruminococcus gnavus group, Eggerthella) associated with CL-2. Relatedly, CL-1 declared higher intakes of fibers and vegetable proteins, whilst CL-2 habitually consumed more saturated fats. We provide the first empirical evidence that simultaneous variations in sensory acuity and gut microbial consortia associate with different dietary habits, thus paving the way for unravelling the complex link between host-related non-genetic factors and aetiology of eating behaviors