Evidence map›Paper›PMID 42260549›Full record

Trial reportNutrition journal2026

Incorporating Euglena gracilis into the habitual diet modulates immune function and reduces common cold-like symptoms: a randomized controlled trial.

Ayaka Nakashima, Wataru Okamoto, Yuka Marukawa-Hashimoto, Tsuyoshi Takara

Abstract readRandomized Controlled Trial
In one paragraph

Trial report in Nutrition journal, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

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

0 citing papers in PubMed.

No citing paper in PubMed yet.

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

4 authors.

Ayaka NakashimaEuglena Co., Ltd., G-BASE Tamachi 2F, 5-29-11, Shiba, Minato-ku, Tokyo, 108-0014, Japan. nakashima@euglena.jp.
Wataru OkamotoEuglena Co., Ltd., G-BASE Tamachi 2F, 5-29-11, Shiba, Minato-ku, Tokyo, 108-0014, Japan.
Yuka Marukawa-HashimotoEuglena Co., Ltd., G-BASE Tamachi 2F, 5-29-11, Shiba, Minato-ku, Tokyo, 108-0014, Japan.
Tsuyoshi TakaraMedical Corporation Seishinkai, Takara Clinic., 9F Taisei Building, 2-3-2 Higashi-gotanda, Shinagawa-ku, Tokyo, 141-0022, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundDietary approaches to support immune function have emphasized the importance of dietary fiber, including non-digestible polysaccharides, although intake remains below recommended levels in many populations. In this context, microalgae have attracted attention as sustainable sources of these components. Euglena gracilis, a microalga used in foods, contains paramylon, a β-1,3-glucan with reported immunomodulatory properties; however, its effects on plasmacytoid dendritic cell (pDC) activation in humans within a dietary context remain incompletely understood.

methodsThis randomized, double-blind, placebo-controlled trial investigated the effects of 8-week E. gracilis intake (1,000 mg/day) on immune function and common cold symptoms in healthy Japanese adults. A total of 200 participants were randomized, of whom 181 (91 in the Euglena group and 90 in the placebo group) were included in the per-protocol analysis. The primary endpoint was the change in the log-transformed median fluorescence intensity (MFI) of CD86 on pDCs at Week 8.

resultsAnalysis using a linear mixed model revealed that the mean ± standard deviation of the log-transformed CD86 MFI at Week 8 was higher in the Euglena group than in the placebo group (placebo: 7.0 ± 2.1; Euglena: 7.7 ± 0.4; group difference 0.7; 95% confidence interval 0.2-1.1; P = 0.004). As exploratory secondary outcomes, the circulating monocyte percentage was higher and the incidence of common cold symptoms-including chills, fatigue, sneezing, rhinorrhea, nasal congestion, sore throat, cough, and headache-was lower in the Euglena group than in the placebo group.

conclusionsThese findings suggest that daily consumption of E. gracilis may support immune function and be associated with a reduced incidence of common cold-like symptoms. The intervention was well tolerated, with no adverse events reported and no clinically meaningful changes in hematological or urinalysis parameters. These findings support the potential of E. gracilis consumption as a viable dietary strategy.

trial registrationUMIN Clinical Trials Registry, UMIN000056125.

Indexed as

Common ColdDietEuglena gracilisAdultB7-2 Antigenbeta-GlucansDendritic CellsDouble-Blind MethodFemaleGlucansHumansJapanMaleMiddle AgedB7-2 Antigenbeta-GlucansGlucansparamylonCold symptomsEuglena gracilisImmune markersParamylonPlasmacytoid dendritic cells

Identifiers

PMID42260549
PMCPMC13483718

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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.