Oral Administration of Flavonifractor plautii Strongly Suppresses Th2 Immune Responses in Mice

Abstract

The bacterium Flavonifractor plautii (FP), which is found in human feces, has been reported to participate in catechin metabolism in the gut, but this bacterium's effects on immune function are unclear. We assessed the effect of oral administration of FP on the immune response in ovalbumin (OVA) -sensitized mice. We demonstrated that the FP treatment suppressed interleukin (IL)-4 in splenocytes and OVA-specific IgE production in serum from OVA-sensitized mice. Moreover, oral administration of FP augmented CD4 + CD25 + T cells and CD103 + CD11c + DCs. In animals of the FP group, the proportion of FP was increased in the mesenteric lymph nodes (MLNs), as was the proportion of Deferribacteres in the cecum. Oral administration of FP may inhibit the Th2 immune response by incorporation into the MLNs and/or by inducing changes in the gut microbiota. Thus, FP may be useful in alleviating antigen-induced Th2 immune responses.

Oral Administration of Flavonifractor plautii, a Bacteria Increased With Green Tea Consumption, Promotes Recovery From Acute Colitis in Mice via Suppression of IL-17

“…FP was purchased from the American Type Culture Collection ( Flavonifractor plautii ATCC® 29863™, Manassas, VA, USA) and cultured as previously described ( 22 ). Briefly, FP was cultured in Gifu Anaerobic Medium (GAM) broth (Nissui Pharmaceutical Co., Ltd., Tokyo, Japan), and the cells were pelleted by centrifugation at 8,000 × g , 4°C for 5 min, and then washed with and resuspended in sterile water to yield a suspension at a density of 1 × 10 11 colony-forming units (cfu)/mL.…”

“…DNA from fecal samples was extracted and purified using a QIAamp Fast DNA Stool Mini kit (Qiagen, Valencia, CA, USA) according to the manufacturer's protocol. FP abundance was measured by quantitative PCR (qPCR) as described previously ( 22 , 25 ). Quantification of the target FP 16S ribosomal DNA (rDNA) levels was performed using the ΔΔCt method, with normalization to the total 16S rDNA content.…”

“…The concentration (cfu/mg) of FP in each sample was calculated by comparing the Ct of the sample with that of the standard curve. Primers and cycling conditions were as described previously ( 22 ).…”

Microbial therapeutics for acute colitis based on genetically modified Lactococcus lactis hypersecreting IL-1Ra in mice

“…Next-generation sequencing samples of day 11 cecal contents were prepared as previously described 19 . Sequencing quality control and trimming of the 341F and 806R forward and reverse primer sequences were conducted using DADA2 20 .…”

Targeting the gut microbiome in allogeneic hematopoietic stem cell transplantation

“…The non-GvHD control associated Flavonifactor plautii has been shown to induce Treg cells in mice [Ogita et al 2020] and, importantly, the white blood cell growth factor GM-CSF in humans [Luna et al 2017]. The non-GvHD control associated Bacteroides uniformis induces IL-10 and Treg in PBMCs and LPMCs [Neff et al 2016].…”