Evidence map›Paper›PMID 41326858›Full record

ArticleApplied microbiology and biotechnology2025

Phosphoserine phosphatase B facilitates indole metabolism to indole-3-lactic acid.

Hiroaki Konishi, Ryo Matsui, Tomomi Okamura, Asahi Imahase, Tsuneyuki Kobayashi, Hiroyuki Nishiyama

Abstract read
In one paragraph

Article in Applied microbiology and biotechnology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Hiroaki KonishiYakult Central Institute, 5-11 Izumi, Kunitachi-Shi, Tokyo, Japan. hiroaki-konishi@yakult.co.jp.
Ryo MatsuiYakult Central Institute, 5-11 Izumi, Kunitachi-Shi, Tokyo, Japan.
Tomomi OkamuraYakult Central Institute, 5-11 Izumi, Kunitachi-Shi, Tokyo, Japan.
Asahi ImahaseYakult Central Institute, 5-11 Izumi, Kunitachi-Shi, Tokyo, Japan.
Tsuneyuki KobayashiYakult Central Institute, 5-11 Izumi, Kunitachi-Shi, Tokyo, Japan.
Hiroyuki NishiyamaYakult Central Institute, 5-11 Izumi, Kunitachi-Shi, Tokyo, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Intestinal bacteria can convert indole to a range of compounds; however, the precise enzymatic processes facilitating this conversion have not been fully elucidated. Certain Bifidobacterium strains convert exogenous indole to indole-3-lactic acid (ILA) via tryptophan synthase beta chain and aromatic lactate dehydrogenase. Moreover, the metabolism of indole is enhanced when the strain is combined with non-digestible oligosaccharides, forming synbiotics. However, the mechanism by which synbiotics enhance indole metabolism remains unclear. Here, the conversion of indole to ILA was investigated in the context of synbiotic-mediated enhancement. The combination of Bifidobacterium bifidum YIT 10347 and galactooligosaccharides (non-digestible oligosaccharides) in human fecal suspension medium synergistically increased this conversion. Screening Tn5 transposon-mutated B. bifidum YIT 10347 clones revealed that phosphoserine phosphatase B (PSP), encoded by serB, and tryptophan synthase alpha chain (TrpA), encoded by trpA, play crucial roles in indole metabolism. Mutant strains lacking either PSP or TrpA showed a significant reduction in ILA production, confirming the roles of PSP and TrpA in this pathway. Additionally, serine supplementation restored ILA production in PSP-deficient strains, further supporting the role of serine biosynthesis in indole metabolism. These results suggest that PSP and TrpA play a vital role in the metabolism of indole to ILA. This study provides novel insights into microbial indole metabolism and suggests potential applications of synbiotics in improving health. KEY POINTS: • PSP and TrpA are essential for indole metabolism • Bifidobacterium bifidum YIT 10347 and GOS synergistically metabolize indole to ILA • This pathway offers potential therapeutic benefits for gut and kidney health.

Indexed as

Bacterial ProteinsBifidobacteriumIndolesLactic AcidPhosphoric Monoester HydrolasesHumansSerineSynbioticsTryptophan SynthaseBacterial Proteinsindoleindole-3-lactic acidIndolesLactic AcidPhosphoric Monoester Hydrolasesphosphoserine phosphataseSerineTryptophan SynthaseBifidobacteriumIndole-3-lactic acidNon-digestible oligosaccharidePhosphoserine phosphatase BTransposonTryptophan synthase alpha chain

Identifiers

PMID41326858
PMCPMC12672768

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LicenceCC BY-NC-ND
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.