Oral Exposure to Polystyrene Microplastics of Mice on a Normal or High-Fat Diet and Intestinal and Metabolic Outcomes

マイクロプラスチックの経口摂取が高脂肪食条件下での代謝障害を悪化させる. 京都大学プレスリリース. 2023-02-24.[Background:] Microplastics (MPs) are small particles of plastic (≤ 5mm in diameter). In recent years, oral exposure to MPs in living organisms has been a cause of concern. Leaky gut syndrome (LGS), associated with a high-fat diet (HFD) in mice, can increase the entry of foreign substances into the body through the intestinal mucosa. [Objectives:] We aimed to evaluate the pathophysiology of intestinal outcomes associated with consuming a high-fat diet and simultaneous intake of MPs, focusing on endocrine and metabolic systems. [Methods:] C57BL6/J mice were fed a normal diet (ND) or HFD with or without polystyrene MP for 4 wk to investigate differences in glucose tolerance, intestinal permeability, gut microbiota, as well as metabolites in serum, feces, and liver. [Results:] In comparison with HFD mice, mice fed the HFD with MPs had higher blood glucose, serum lipid concentrations, and nonalcoholic fatty liver disease (NAFLD) activity scores. Permeability and goblet cell count of the small intestine (SI) in HFD-fed mice were higher and lower, respectively, than in ND-fed mice. There was no obvious difference in the number of inflammatory cells in the SI lamina propria between mice fed the ND and mice fed the ND with MP, but there were more inflammatory cells and fewer anti-inflammatory cells in mice fed the HFD with MPs in comparison with mice fed the HFD without MPs. The expression of genes related to inflammation, long-chain fatty acid transporter, and Na⁺/glucose cotransporter was significantly higher in mice fed the HFD with MPs than in mice fed the HFD without MPs. Furthermore, the genus Desulfovibrio was significantly more abundant in the intestines of mice fed the HFD with MPs in comparison with mice fed the HFD without MPs. Muc2 gene expression was decreased when palmitic acid and microplastics were added to the murine intestinal epithelial cell line MODE-K cells, and Muc2 gene expression was increased when IL-22 was added. [Discussion:] Our findings suggest that in this study, MP induced metabolic disturbances, such as diabetes and NAFLD, only in mice fed a high-fat diet. These findings suggest that LGS might have been triggered by HFD, causing MPs to be deposited in the intestinal mucosa, resulting in inflammation of the intestinal mucosal intrinsic layer and thereby altering nutrient absorption. These results highlight the need for reducing oral exposure to MPs through remedial environmental measures to improve metabolic disturbance under high-fat diet conditions

Maternal Awareness and Involvement in Early Childhood Home Education about Life and Death

本研究の目的は、幼児の母親を対象に、家庭でのいのちの教育に対する母親の意識と子どもへの関わりについて明らかにすることである。研究方法は、関東圏在住の母親８人に、60分程度の半構成的面接を行った。その結果、【混在する死のイメージと捉え方の変化】【幼少期からの死に関する体験】【妊娠・出産で深まったいのちや生に対する意識】【妊娠・出産を通して児から感じるいのちの存在】【妊娠・出産を通したいのちの教育】【子どもの成長や保育園に合わせた関わり】【生き物を通した夫婦での補完的な関わり】の７のカテゴリー、22のサブカテゴリーを抽出した。母親自身が、いのちの教育への意識が乏しく機会がないと感じながらも、妊娠・出産でいのちや生に対する意識が深まり、いのちの大切さを伝えたいと考えていた。また、妊娠・出産時から子どもに意図的に関わり、保育園でのいのちの教育を活かし、夫婦で子どもに関わっていた。departmental bulletin pape

Quantification of hydrogen production by intestinal bacteria that are specifically dysregulated in Parkinson's disease.

Oral administration of hydrogen water ameliorates Parkinson's disease (PD) in rats, mice, and humans. We previously reported that the number of putative hydrogen-producing bacteria in intestinal microbiota is low in PD compared to controls. We also reported that the amount of hydrogen produced by ingestion of lactulose is low in PD patients. The decreased hydrogen production by intestinal microbiota may be associated with the development and progression of PD. We measured the amount of hydrogen production using gas chromatography by seven bacterial strains, which represented seven major intestinal bacterial groups/genera/species. Blautia coccoides and Clostridium leptum produced the largest amount of hydrogen. Escherichia coli and Bacteroides fragilis constituted the second group that produced hydrogen 34- to 93-fold lower than B. coccoides. Bifidobacterium pseudocatenulatum and Atopobium parvulum constituted the third group that produced hydrogen 559- to 2164-fold lower than B. coccoides. Lactobacillus casei produced no detectable hydrogen. Assuming that taxonomically neighboring strains have similar hydrogen production, we simulated hydrogen production using intestinal microbiota that we previously reported, and found that PD patients produce a 2.2-fold lower amount of intestinal hydrogen compared to controls. The lower amount of intestinal hydrogen production in PD was also simulated in cohorts of two other countries. The number of hydrogen-producing intestinal bacteria may be associated with the development and progression of PD. Further studies are required to prove its beneficial effect