SAMEA111406162 ERS13500036 uncultured Lachnospiraceae bacterium This sample represents a Third Party Annotation (TPA) Metagenome-Assembled Genome (MAG) assembled from the metagenomic run ERR5647205 of study ERP128045. EBI Generic Generic.1.0 ERC000047 2022-09-28 2022-09-28 SAMEA111406162 EMG EMG 2022-09-28T12:19:35Z 2022-09-28T12:19:35Z public ERR5647205_bin.1_metawrap_v1.3_MAG Many fragments with little to no review of assembly other than reporting of standard assembly statistics metaSPAdes v3.15.3 MaxBin2, MetaBat2, Concoct with default parameter of the metaWRAP pipeline. Bin refinement module used from metaWRAP with default parameters. metawrap v1.3 mouse digestive system EMG broker account, EMBL-EBI not provided 95.86 CheckM 2.59 feces not provided not provided not provided metagenome-assembled genome mouse gut metagenome digestive tube mouse gut metagenome Autism spectrum disorder (ASD) is one of the most severe developmental disorders, affecting on average 1 in 150 children worldwide. There is a great need for more effective strategies to improve quality of life in ASD subjects. The gut microbiome has emerged as a potential therapeutic target in ASD. A novel modulator of the gut microbiome, the traditionally fermented milk drink kefir, has recently been shown to modulate the microbiota and decrease repetitive behaviour, one of the hallmarks of ASD, in mice. As such, we hypothesized that kefir could ameliorate behavioural deficits in a mouse model relevant to ASD; the BTBR T+ Itpr3tf/J mouse strain. To this end, adult mice were administered either kefir (UK4) or a milk control for three weeks as treatment lead-in, after which they were assessed for their behavioural phenotype using a battery of tests. In addition, we assessed systemic immunity by flow cytometry and the gut microbiome using shotgun metagenomic sequencing. We found that indeed kefir decreased repetitive behaviour in this mouse model. Furthermore, kefir prolonged stress-induced increases in corticosterone 60 min post-stress, which was accompanied by an ameliorated innate immune response as measured by LY6Chi monocyte levels. In addition, kefir increased the levels of anti-inflammatory Treg cells in mesenteric lymph nodes (MLNs). Kefir also increased the relative abundance of Lachnospiraceae bacterium A2, which correlated with reduced repetitive behaviour and increased Treg cells in MLNs. Functionally, kefir modulated various predicted gut microbial pathways, including the gut-brain module S-Adenosylmethionine (SAM) synthesis, as well as L-valine biosynthesis and pyruvate fermentation to isobutanol, which all correlated with repetitive behaviour. Taken together our data show that kefir modulates peripheral immunoregulation, can ameliorate specific ASD behavioural dysfunctions and modulates selective aspects of the composition and function of the gut microbiome, indicating that kefir supplementation might prove a viable strategy in improving quality of life in ASD subjects. SAMEA8498354 ERR5647205_bin.1_metawrap_v1.3_MAG NextSeq 500 The taxonomy of this metagenome-assembled genome was originally computed with GTDBtk, which assigned the following taxonomic annotation: d__Bacteria;p__Firmicutes;c__Clostridia;o__Clostridiales;f__Lachnospiraceae;g__;s__ multi-marker approach