Hiroto Miura

Dr. Hiroto Miura


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 August 2022 in Animals
Verified
Journal Article
Open access
PDF file
HMHiroto Miura
Hiroto Miura
IJItsuki Jimbo
Itsuki Jimbo
MOMachi Oda
Machi Oda
MNMichiko Noguchi
Michiko Noguchi
KKKiyonori Kawasaki
Kiyonori Kawasaki
RIRyo Inoue
Ryo Inoue
Growing evidence indicates that porcine colostral exosomes may contribute to the healthy development of piglets. Here, we evaluated in vitro the effect of porcine milk-derived exosomes, in particular colostral exosomes, on T cells in the peripheral blood of suckling piglets. A total of seven sows and thirteen suckling piglets were used. Peripheral blood mononuclear cells (PBMCs) from suckling piglets were cultured with or without milk-derived exosomes (control). Using flow cytometry, the proportion of each T cell subset in cultured PBMCs was analyzed three days post-incubation. PBMCs cultured with porcine colostral exosomes had a higher proportion of CD3+CD4−CD8+ T cells (cytotoxic T cells; Tc) than the control. However, exosomes induced no increase in the Tc cell population in PBMC whose endocytosis was inhibited. We further measured the concentrations of cytokines in the culture supernatant. Exosome-treated PBMCs had a higher cytokine IL-2 concentration than the control. The present study demonstrated that porcine colostral exosomes could increase the Tc cell proportion in the peripheral blood of suckling piglets, with the underlying mechanism believed to be the stimulation of IL-2 production in PBMCs via endocytosis. Moreover, our results suggested that porcine colostral exosomes were involved in the development of cellular immunity in suckling piglets.

2 July 2025 in Microorganisms
Verified
Journal Article
Open access
PDF file
HMHiroto Miura
Hiroto Miura
MOMachi Oda
Machi Oda
KAKanako Abe
Kanako Abe
HIHiromi Ikeda
Hiromi Ikeda
MFMami Fujibayashi
Mami Fujibayashi
RIRyo Inoue
Ryo Inoue
Our previous study reported that male university rugby players tended to have a gut with a dysbiotic environment, characterized by abundant pathobiont bacteria and an accumulation of succinate, when compared with age-matched, non-rugby playing healthy males. In the present study, we conducted a randomized, double-blinded, placebo-controlled experiment to evaluate the potential of blackcurrant extract and/or partially hydrolyzed guar gum (PHGG) to improve the gut environment of university rugby players. Participants were supplemented with blackcurrant extract and/or PHGG or a placebo for 4 weeks. Beneficial gut bacteria such as Megasphaera spp. tended to increase (p < 0.10) and Bifidobacterium spp. increased (p < 0.05) with the intake of blackcurrant extract and/or PHGG. A subgroup analysis further indicated that, unlike in those with a eubiotic gut environment, the dietary supplements also increased the number of beneficial gut bacteria such as Phascolarctobacterium spp. (p < 0.10) and Faecalibacterium spp. (p < 0.10) and fecal SCFA concentrations (p < 0.05) in participants with a possible dysbiotic gut environment. However, a synergistic effect between blackcurrant extract and PHGG was not clearly observed. Although further investigation is recommended, it was concluded that blackcurrant extract and PHGG can at least be used as functional materials to improve gut dysbiosis in university rugby players.

29 October 2024 in Microorganisms
Verified
Journal Article
Open access
PDF file
HMHiroto Miura
Hiroto Miura
TTTakamitsu Tsukahara
Takamitsu Tsukahara
RIRyo Inoue
Ryo Inoue
Recent studies suggested an association between the reproductive performance of sows and their gut microbiota. To understand how the gut microbiota affect the reproductive performances of sows, we conducted a whole-genome metagenomic analysis on the fecal microbial functional profiles of sows with high and low reproductive performances. We used 60 sows from six farms (10 sows/farm), including 30 sows from three farms with higher reproductive performances (the mean number of weaned piglets/sow/year) (group H) and 30 sows from three farms with lower performances (group L). Fecal microbial DNA was subjected to a whole-genome metagenomic analysis. Biomarker exploration analysis identified “carbohydrate transport and metabolism” as the most discriminative function enriched in group H. Further analysis of carbohydrate-active enzymes revealed that the fecal microbiome of group H had a greater capacity to degrade dietary fiber, specifically cellulose and pectin. Group H also exhibited higher fecal short-chain fatty acid (SCFA) concentrations than group L, with the abundances of cellulose- and pectin-degrading genes showing significant positive correlations with fecal SCFA concentrations. Taxonomic analysis indicated greater contributions of Prevotella, Treponema, Ruminococcus, and Fibrobacter to cellulose and pectin degradation in the fecal microbiome in group H. In conclusion, higher reproductive performances of sows were, at least in part, associated with a greater microbial capacity for degrading cellulose and pectin, resulting in a higher SCFA production in the hindgut.

24 January 2025 in Microorganisms
Verified
Journal Article
Open access
PDF file
SYShu Yoshimura
Shu Yoshimura
TTTakamitsu Tsukahara
Takamitsu Tsukahara
TTToru Takahashi
Toru Takahashi
HMHiroto Miura
Hiroto Miura
SMSo Morishima
So Morishima
RIRyo Inoue
Ryo Inoue
The aim of this study was to investigate the microbiota composition and its potential interactions across seven gut locations (stomachs, jejuna, ilea, ceca, proximal colons, distal colons, and recta) in weaned pigs to identify key influencing microbiotas. To compare between microbiota compositions, 16S rRNA gene amplicon sequencing was performed. Six 70-day-old healthy crossbred (Duroc × Large White × Landrace) piglets were introduced as donors. A Bayesian network (BN) was used to examine the directional interactions among the microbiotas evaluated (seven mucosal and seven digesta microbiotas). Based on edge connectivity frequency, the microbiota in jejunal mucosa was the central hub node, influencing other microbiotas, especially the mucosal microbiotas of the ileum, cecum, distal colon, and rectum. The jejunal mucosa was dominated by Prevotella and lactobacilli, both recognized for their contributions to pig health. Among Prevotella, Prevotella copri and Prevotella sp. were predominant in jejunal mucosa (4.6% and 2.9%, respectively). Lactobacilli, including eight distinct species, were distributed throughout the gastrointestinal tract. Notably, Ligilactobacillus salivarius and Lactobacillus amylovorus, known as immune-enhancing bacteria, were abundant in jejunal mucosa (1.0% and 0.8%) and digestas (0.9% and 19.2%), respectively. The BN identified rectal mucosa and digestas as two terminal nodes, influenced by upstream microbiotas in the gastrointestinal tract. This finding supports the link between fecal microbiota and pig productivity, as the fecal microbiota, closely resembling the rectal microbiota, reflects the conditions of the microbiota throughout the gastrointestinal tract.

22 October 2025 in Metabolites
Verified
Journal Article
Open access
PDF file
TTTakamitsu Tsukahara
Takamitsu Tsukahara
HMHiroto Miura
Hiroto Miura
TKTakahiro Kawase
Takahiro Kawase
SYShu Yoshimura
Shu Yoshimura
YMYoshihiro Mizukami
Yoshihiro Mizukami
RIRyo Inoue
Ryo Inoue
Background: Sow reproductive performance is a critical parameter for the productivity of commercial pig farms. Gut microbiota is associated with performance in sow reproduction. At least, under healthy conditions, microbial metabolites from the gut microbiota are considered major contributors to host physiological regulation and productivity. However, information on the differences in gut-derived metabolites related to the sow reproductive performance remain scarce. Our aim was to investigate the relationship between the reproductive performance and microbial metabolite levels in sow’s feces and plasma. Methods: We selected four commercial farms: two with high- (group H) and two with low-reproductive performance (group L). Sows had their feces and blood collected. Results: Except for the iso-butyrate concentration, fecal short-chain fatty acid concentrations remained unchanged between groups. Among intestinal putrefactive metabolites, the indole concentration was higher (p < 0.05) in group H. The concentrations of plasma metabolites p-cresyl sulfate, p-cresyl glucuronide and trimethylamine N-oxide (TMAO) were higher (p < 0.05) in group L than in group H, while the opposite was true for the acetate concentration (p < 0.05). Among plasma biochemicals, tumor necrosis factor (TNF)-alpha and potassium concentrations were higher (p < 0.05) in group L. Conclusions: Blood metabolites, especially gut microbiota-derived metabolites, seemed to be associated with the performance related to sow reproduction. Particularly, harmful metabolites such as p-cresyl glucuronide, p-cresyl sulfate and TMAO were of importance, because they are potentially inflammation factors. In fact, TNF-alpha was stimulated in group L. According to our results, we estimated that p-cresyl glucuronide, p-cresyl sulfate, TMAO and TNF-alpha could be useful physiological indicators to understand sow reproductive performance.