Gut microbiota as a potential target for developing anti-fatigue foods

Longitudinal associations of dietary intake with fatigue in colorectal cancer survivors up to 1 year post-treatment, and the potential mediating role of the kynurenine pathway

INTRODUCTION

A healthy diet may help to reduce cancer-related fatigue, but evidence is limited and mechanisms remain unclear. Both diet and fatigue following colorectal cancer (CRC) have been linked to metabolites (kynurenines) of the kynurenine pathway (KP). We investigated longitudinal associations between dietary intake and fatigue, and the potential mediating role of the KP, in CRC survivors up to 1 year post-treatment.

METHODS

Measurements at 6 weeks, 6 months, and 1 year post-treatment were performed in 209 stage I-III CRC survivors. Diet was assessed by 7-day food records. Plasma kynurenines were analyzed using LC-MS/MS. Fatigue, including subjective fatigue, was assessed using validated questionnaires. To analyse longitudinal associations between diet and fatigue and to explore potential mediation by the KP, we used confounder-adjusted multilevel parallel-multiple mediator models with all kynurenines included simultaneously, and simple mediator models with established KP ratios to estimate total (c: diet-fatigue), direct (c': diet-fatigue, while controlling for mediators), metabolite-specific indirect (ab: diet-metabolite-fatigue), and total indirect (ab: diet-metabolites-fatigue) effects.

RESULTS

Higher intake of total carbohydrates and mono- and disaccharides was longitudinally associated with more subjective fatigue, while higher intake of plant protein, total fat, and unsaturated fats was associated with less subjective fatigue (c). Most associations remained statistically significant after controlling for KP metabolites, except for mono- and disaccharides (c'). All kynurenines simultaneously did not mediate longitudinal associations between diet and subjective fatigue (ab). The kynurenic acid-to-quinolinic acid (KA/QA) ratio significantly mediated associations of intakes of carbohydrate, mono- and disaccharides, alcohol, magnesium, and zinc with subjective fatigue, whereas the HKr significantly mediated the association between polysaccharide intake and subjective fatigue (ab).

CONCLUSION

Our findings suggest that carbohydrate intake is associated with greater fatigue, while protein and fat intake are associated with lower fatigue in CRC survivors up to 1 year post-treatment. While all KP metabolites simultaneously did not significantly mediate associations between diet and fatigue in our population, the KA/QA ratio and HKr were significant mediators in several diet-fatigue associations. These results should be repeated in larger observational studies.

Blending polysaccharides from three edible mushrooms represents a promising approach for augmenting their anti-oxidant and anti-fatigue activities

It has been well documented that a number of polysaccharides with potent free-radical scavenging capability possess notable anti-fatigue activity. Interestingly, recent evidence also suggested mixed polysaccharides derived from multiple sources may yield augmented bioactivities compared to the polysaccharides from a single source. Therefore, in the current study, we investigated the anti-oxidant and anti-fatigue activities of a blend of polysaccharides isolated from three mushrooms. The optimal ratio of Pleurotus eryngii polysaccharide, Agrocybe aegerita polysaccharide, and Agaricus bisporus polysaccharide was firstly screened out by in vitro antioxidant assays with a Z-score comprehensive evaluation method. Then, the fatigue-reducing effects of the polysaccharide mixture at optimal ratio (1:2:2) were studied in mice. The results showed that the polysaccharide mixture exerted desirable fatigue-reducing effect evidence by significantly extended exhaustion time in the weight-loaded swimming assay (from 9.45 ± 3.06 min to 27.65 ± 19.84 min). Moreover, the observed fatigue-reducing effect may be attributed to its capacity to decrease fatigue-related metabolites, increase muscle glycogen reserves, and regulate energy metabolism-related transcripts in muscle tissue. Taken together, these findings highlighted the potential application of blending polysaccharides from multiple mushroom sources in mitigating fatigue.

Ethanol extract of propolis relieves exercise-induced fatigue via modulating the metabolites and gut microbiota in mice

Background

Propolis, a natural mixture rich in bioactive compounds, has shown the potential to relieve exercise-induced fatigue. However, the underlying mechanism remains unclear. This study aimed to explore the anti-fatigue effects of ethanol extract of propolis (EEP) and its potential mechanisms.

Methods

Male C57BL/6 mice aged 6-8 weeks were subjected to swim training with or without EEP supplementation (400 mg/kg.bw) for 3 weeks, followed by a exhaustive swimming test to simulate exercise-induced fatigue. The exhaustion time and fatigue-related biochemical indices were measured to assess the anti-fatigue effects. The anti-fatigue mechanism of EEP was further investigated using untargeted serum metabolomics and 16S rRNA gene sequencing of the gut microbiota.

Results

The results showed that supplementation with EEP significantly increased the exhaustive swimming time of the mice by 27.64%, with no significant effects on body weight, food intake, or viscera and muscle index among the 3 groups. Biochemical analysis indicated that EEP effectively alleviated fatigue-related biochemical indices caused by excessive exercise, including liver glycogen (LG), muscle glycogen (MG), blood lactate (BLA), blood urea nitrogen (BUN), lactate dehydrogenase (LDH), interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), superoxide dismutase (SOD), total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA). Serum metabolomics analysis revealed that EEP reversed the levels of 6 key metabolites (Gamma-Aminobutyric acid, pipecolic acid, L-isoleucine, sucrose, succinic acid, and L-carnitine), which are involved in 7 metabolic pathways related to energy metabolism, amino acid metabolism, and carbohydrate metabolism. 16S rRNA sequencing analysis of the cecal contents showed that EEP altered the composition and structure of the gut microbiota, increasing the abundance of butyrate-producing bacteria and reducing the abundance of harmful bacteria. Correlation analysis revealed that specific bacterial genera were closely related to certain differential metabolites and biochemical indices.

Conclusion

Our study showed that EEP significantly increased exercise endurance in mice and exerted anti-fatigue effects by modulating key metabolites and the gut microbiota.

Moderate Highland Barley Intake Affects Anti-Fatigue Capacity in Mice via Metabolism, Anti-Oxidative Effects and Gut Microbiota

OBJECTIVES

this study aimed to explore the effects of different intake levels (20-80%) of highland barley on the anti-fatigue capacity of ICR mice, focusing on energy metabolism, metabolite accumulation, oxidative stress, and changes in the gut microbiota.

METHODS

male ICR mice were assigned to five groups: control (normal diet) and four experimental groups with highland barley supplementation at 20%, 40%, 60%, and 80% of total dietary energy. Anti-fatigue performance was assessed by behavioral experiments (rotarod, running, and exhaustive swimming tests), biochemical markers, and gut microbiota analysis.

RESULTS

the results showed that moderate supplementation (20%) significantly enhanced exercise endurance and anti-fatigue capacity, as evidenced by increased liver glycogen (134.48%), muscle glycogen (87.75%), ATP content (92.07%), Na+-K+-ATPase activity (48.39%), and antioxidant enzyme activities (superoxide dismutase (103.31%), catalase (87.75%), glutathione peroxidase (81.14%). Post-exercise accumulation of blood lactate, quadriceps muscle lactate, serum urea nitrogen, and the oxidative stress marker malondialdehyde was significantly reduced, with differences of 31.52%, 21.83%, 21.72%, and 33.76%, respectively. Additionally, 20% supplementation promoted the growth of beneficial gut microbiota associated with anti-fatigue effects, including unclassified_f_Lachnospiraceae, g_norank_f_Peptococcaceae, Lachnospiraceae NK4A136, Colidextribacter, and Turicibacter. However, when intake reached 60% or more, anti-fatigue effects diminished, with decreased antioxidant enzyme activity, increased accumulation of metabolic waste, and a rise in potentially harmful microbiota (Allobaculum, Desulfovibrio, and norank_f_norank_o_RF39).

CONCLUSIONS

moderate highland barley supplementation (20% of total dietary energy) enhances anti-fatigue capacity, while excessive intake (≥60%) may have adverse effects.

Sources, metabolism, health benefits and future development of saponins from plants

Saponins are a class of glycoside compounds whose aglycones are triterpenoids or spirostanes, widely exist in a variety of Chinese herbs. Saponins are one of the important active components of medicinal plants and have a wide range of bioactivities. In order to promote the better development and utilization of saponins, the process of digestion, absorption and metabolism of saponins in vivo was reviewed in this paper. At the same time, the main bioactivities of common saponins and their potential mechanisms for alleviating diseases were summarized. Finally, the potential of saponins as functional food has been pointed out, and microbial transformation can make saponins better play this potential in the future.

Clinical study of Jianpi Qingchang decoction in the treatment of ulcerative colitis patients with spleen deficiency and dampness-heat syndrome accompanied by fatigue: Study protocol for a randomized controlled trial

BACKGROUND

Ulcerative colitis (UC) is a chronic non-specific inflammatory intestinal disease, categoried under "dysentery" and "intestinal bleeding" in Traditional Chinese Medicine (TCM). Jianpi Qingchang decoction (JPQC) is a combination formula specifically designed for the treatment of UC. The primary objective of this study is to examine the clinical efficacy of JPQC in individuals diagnosed with UC who exhibit both spleen deficiency and dampness-heat syndrome, along with the presence of fatigue. The investigation will focus on assessing the impact of JPQC on the gut microbiota and metabolites in these patients, aiming to elucidate the regulatory mechanism that JPQC exerts on the gut microbiota and metabolites in the context of UC-related fatigue.

METHODS

In this randomized clinical trial, 140 subjects diagnosed with UC will be recruited and randomized into two groups. They will receive either JPQC combined with mesalazine or mesalazine alone for 12 weeks. Follow-up visits will be conducted every four weeks, with a post-treatment visit scheduled at 6 months. The primary outcome measures include the Inflammatory bowel disease fatigue scale(IBD-F). Secondary efficacy indicators comprise the assessment of TCM syndrome and individual syndrome efficacy before and after treatment, Modified Mayo score, Simple clinical colitis activity index (SCCAI), as well as the Inflammatory Bowel Disease Questionnaire (IBDQ) for each group. The other outcomes are the Intestinal microbial diversity and non-targeted metabonomics, which will be measured at baseline and 12 weeks after randomization.

DISCUSSION

If effective, JPQC will provide substantial clinical evidence concerning the effectiveness and safety in the treatment of patients with UC experiencing spleen deficiency and dampness-heat syndrome accompanied by fatigue.

TRIAL REGISTRATION

ChiCTR2300068348.

Advances in relieving exercise fatigue for curcumin: Molecular targets, bioavailability, and potential mechanism

Intense and prolonged physical activity can lead to a decrease in muscle capacity, making it difficult to maintain the desired exercise intensity and resulting in exercise fatigue. The long-term effects of exercise fatigue can be very damaging to the body, so it is an urgent problem to be addressed. The intervention of foodborne active substances will be an effective measure. There is growing evidence that the molecular structure and function of curcumin have a positive effect on relieving fatigue. In this review, we summarize curcumin's molecular structure, which enables it to bind to a wealth of molecular targets, regulate signaling pathways, and thus alleviate exercise fatigue through a variety of mechanisms, including reducing oxidative stress, inhibiting inflammation, reducing metabolite accumulation, and regulating energy metabolism. The effects of curcumin on fatigue-related markers were analyzed from the perspective of animal models and human models and based on the bidirectional interaction between curcumin and intestinal microbiota: Intestinal microbiota can transform curcumin, and curcumin regulates gut microbiota through metabolic pathways, providing a new perspective for alleviating fatigue. This review contributes to a more comprehensive understanding of the possible molecular mechanisms of curcumin in anti-fatigue and provides a new possibility for the development of functional foods in the future.

Evaluating the Impact of Probiotic Therapy on the Endocannabinoid System, Pain, Sleep and Fatigue: A Randomized, Double-Blind, Placebo-Controlled Trial in Dancers

Emerging research links the endocannabinoid system to gut microbiota, influencing nociception, mood, and immunity, yet the molecular interactions remain unclear. This study focused on the effects of probiotics on ECS markers-cannabinoid receptor type 2 (CB2) and fatty acid amide hydrolase (FAAH)-in dancers, a group selected due to their high exposure to physical and psychological stress. In a double-blind, placebo-controlled trial (ClinicalTrials.gov NCT05567653), 15 dancers were assigned to receive either a 12-week regimen of Lactobacillus helveticus Rosell-52 and Bifidobacterium longum Rosell-17 or a placebo (PLA: n = 10, PRO: n = 5). There were no significant changes in CB2 (probiotic: 0.55 to 0.29 ng/mL; placebo: 0.86 to 0.72 ng/mL) or FAAH levels (probiotic: 5.93 to 6.02 ng/mL; placebo: 6.46 to 6.94 ng/mL; p > 0.05). A trend toward improved sleep quality was observed in the probiotic group, while the placebo group showed a decline (PRO: from 1.4 to 1.0; PLA: from 0.8 to 1.2; p = 0.07841). No other differences were noted in assessed outcomes (pain and fatigue). Probiotic supplementation showed no significant impact on CB2 or FAAH levels, pain, or fatigue but suggested potential benefits for sleep quality, suggesting an area for further research.

Polysaccharides from Polygonatum kingianum Collett & Hemsl ameliorated fatigue by regulating NRF2/HO-1/NQO1 and AMPK/PGC-1α/TFAM signaling pathways, and gut microbiota

Polygonatum kingianum Coll & Hemsl is an important Chinese medicine used for enhancing physical function and anti-fatigue, and polysaccharides (PKPs) are considered as the main bioactive components. However, the mechanisms through which PKPs exert their anti-fatigue effects are not fully understood. This study aimed more comprehensively to explore the anti-fatigue mechanisms of PKPs, focusing on metabolism, protein expression, and gut flora, by using exhaustive swimming experiments in mice. Results showed a significant increase in the exhaustive swimming time of the mice treated with PKPs, especially in the high-dose group (200 mg/kg/day). Further studies showed that PKPs remarkably improves several fatigue-related physiological indices. Additionally, 16S rRNA sequence analysis showed that PKPs increased antioxidant bacteria (e.g., g_norank_f_Muribaculaceae) and the production of short-chain fatty acids (SCFAs), while reducing the abundance of harmful bacteria (e.g., g_Escherichia-Shigella and g_Helicobacter). PKPs also mitigated oxidative stress through activating the NRF2/HO-1 signaling pathway, and promoted energy metabolism by upregulating the expression of AMPK/PGC-1α/TFAM signaling pathway proteins. This research may offer theoretical support for incorporating PKPs as a novel dietary supplement in functional foods targeting anti-fatigue properties.

Metabolome and microbiome analyses of the anti-fatigue mechanism of Acanthopanax senticosus leaves

Acanthopanax senticosus leaves, widely used as a vegetable and tea, are reported to be beneficial in treating neurological disorders. At present, their anti-fatigue effect remains to be established. In this study, we analyzed the composition of the extracts from A. senticosus leaves and confirmed their antioxidant and anti-inflammatory properties at the cellular level. In mice subjected to exhaustive running on a treadmill, supplementation with A. senticosus leaf extracts enhanced exercise performance and alleviated fatigue via the reversal of exercise-induced 5-HT elevation, metabolic waste accumulation, organ damage, and glucose metabolism-related gene expression. The collective findings from microbiome and metabolomic analyses indicate that A. senticosus leaf extracts increase α-diversity, regulate microbial composition, and reverse exercise-mediated disruption of carbohydrate, creatine, amino acid, and trimethylamine metabolism. This study provides preliminary evidence for the utility of A. senticosus leaves as a promising anti-fatigue food and offers insights into the underlying mechanism.

Camellia oil exhibits anti-fatigue property by modulating antioxidant capacity, muscle fiber, and gut microbial composition in mice

Camellia seed oil (CO) has high nutritional value and multiple bioactivities. However, the specific anti-fatigue characteristics and the implied mechanism of CO have not yet been fully elucidated. Throughout this investigation, male C57BL/6J mice, aged 8 weeks, underwent exhaustive exercise with or without CO pretreatment (2, 4, and 6 mL/kg BW) for 28 days. CO could extend the rota-rod and running time, reduce blood urea nitrogen levels and serum lactic acid, and increase muscle and hepatic glycogen, adenosine triphosphate, and anti-oxidative indicators. Additionally, CO could upregulate the mRNA and Nrf2 protein expression levels, as well as enhance the levels of its downstream antioxidant enzymes and induce the myofiber-type transformation from fast to slow and attenuate the gut mechanical barrier. Moreover, CO could ameliorate gut dysbiosis by reducing Firmicutes to Bacteroidetes ratio at the phylum level, increasing the percentage of Alistipes, Alloprevotella, Lactobacillus, and Muribaculaceae, and decreasing the proportion of Dubosiella at the genus level. In addition, specific bacterial taxa, which were altered by CO, showed a significant correlation with partial fatigue-related parameters. These findings suggest that CO may alleviate fatigue by regulating antioxidant capacity, muscle fiber transformation, gut mechanical barrier, and gut microbial composition in mice. PRACTICAL APPLICATION: Our study revealed that camellia seed oil (CO) could ameliorate exercise-induced fatigue in mice by modulating antioxidant capacity, muscle fiber, and gut microbial composition in mice. Our results promote the application of CO as an anti-fatigue functional food that targets oxidative stress, myofiber-type transformation, and microbial community.

Aqueous Extract of Brassica rapa L.'s Impact on Modulating Exercise-Induced Fatigue via Gut-Muscle Axis

Exercise-induced fatigue is a common physiological response to prolonged physical activity, often associated with changes in gut microbiota and metabolic responses. This study investigates the potential role of Brassica rapa L. in modulating these responses. Using an animal model subjected to chronic exercise-induced stress, we explored the effects of Brassica rapa L. on fatigue-related biomarkers, energy metabolism genes, inflammatory responses, intestinal integrity, and gut microbiota composition. Our findings revealed that Brassica rapa L. exhibits significant antioxidant activity and effectively modulates physiological responses to fatigue. It influences gene expression related to the tricarboxylic acid (TCA) cycle in muscle tissue through the AMPK/PGC-1α/TFAM signaling pathway. Furthermore, Brassica rapa L. has been found to alleviate inflammation by inhibiting lipopolysaccharide (LPS) infection and suppressing the activation of the NF-κB pathway. It also maintains intestinal integrity and controls Gram-negative bacterial growth. A correlation analysis identified several pathogenic bacteria linked with inflammation and energy metabolism, as well as beneficial probiotic bacteria associated with improved energy metabolism and reduced inflammation. These findings underscore Brassica rapa L.'s potential for managing prolonged exercise-induced fatigue, paving the way for future therapeutic applications. The results highlight its impact on gut microbiota modulation and its role in nutrition science and sports medicine.

Dietary Polysaccharides Exert Anti-Fatigue Functions via the Gut-Muscle Axis: Advances and Prospectives

Due to today's fast-paced lifestyle, most people are in a state of sub-health and face "unexplained fatigue", which can seriously affect their health, work efficiency, and quality of life. Fatigue is also a common symptom of several serious diseases such as Parkinson's, Alzheimer's, cancer, etc. However, the contributing mechanisms are not clear, and there are currently no official recommendations for the treatment of fatigue. Some dietary polysaccharides are often used as health care supplements; these have been reported to have specific anti-fatigue effects, with minor side effects and rich pharmacological activities. Dietary polysaccharides can be activated during food processing or during gastrointestinal transit, exerting unique effects. This review aims to comprehensively summarize and evaluate the latest advances in the biological processes of exercise-induced fatigue, to understand dietary polysaccharides and their possible molecular mechanisms in alleviating exercise-induced fatigue, and to systematically elaborate the roles of gut microbiota and the gut-muscle axis in this process. From the perspective of the gut-muscle axis, investigating the relationship between polysaccharides and fatigue will enhance our understanding of fatigue and may lead to a significant breakthrough regarding the molecular mechanism of fatigue. This paper will provide new perspectives for further research into the use of polysaccharides in food science and food nutrition, which could help develop potential anti-fatigue agents and open up novel therapies for sub-health conditions.

Microbiota and mycobiota in bronchoalveolar lavage fluid of silicosis patients

BACKGROUND

The contribution of bronchoalveolar lavage fluid (BALF) microbiota and mycobiota to silicosis has recently been noticed. However, many confounding factors can influence the accuracy of BALF microbiota and mycobiota studies, resulting in inconsistencies in the published results. In this cross-sectional study, we systematically investigated the effects of "sampling in different rounds of BALF" on its microbiota and mycobiota. We further explored the relationship between silicosis fatigue and the microbiota and mycobiota.

METHODS

After obtaining approval from the ethics board, we collected 100 BALF samples from 10 patients with silicosis. Demographic data, clinical information, and blood test results were also collected from each patient. The characteristics of the microbiota and mycobiota were defined using next-generation sequencing. However, no non-silicosis referent group was examined, which was a major limitation of this study.

RESULTS

Our analysis indicated that subsampling from different rounds of BALF did not affect the alpha- and beta-diversities of microbial and fungal communities when the centrifuged BALF sediment was sufficient for DNA extraction. In contrast, fatigue status significantly influenced the beta-diversity of microbes and fungi (Principal Coordinates Analysis, P = 0.001; P = 0.002). The abundance of Vibrio alone could distinguish silicosis patients with fatigue from those without fatigue (area under the curve = 0.938, 95% confidence interval [CI] 0.870-1.000). Significant correlations were found between Vibrio and haemoglobin levels (P < 0.001, ρ = -0.64).

CONCLUSIONS

Sampling in different rounds of BALF showed minimal effect on BALF microbial and fungal diversities; the first round of BALF collection was recommended for microbial and fungal analyses for convenience. In addition, Vibrio may be a potential biomarker for silicosis fatigue screening.

Interactions between Gut Microbiota and Polyphenols: New Insights into the Treatment of Fatigue

Fatigue seriously affects people's work efficiency and quality of life and has become a common health problem in modern societies around the world. The pathophysiology of fatigue is complex and not fully clear. To some degree, interactions between gut microbiota and host may be the cause of fatigue progression. Polyphenols such as tannin, tea polyphenols, curcumin, and soybean isoflavones relieve fatigue significantly. Studies have shown that the gut microbiota is able to convert these active compounds into more active metabolites through intestinal fermentation. However, the mechanism of anti-fatigue polyphenols is currently mainly analyzed from the perspective of antioxidant and anti-inflammatory effects, and changes in gut microbiota are rarely considered. This review focuses on gut microecology and systematically summarizes the latest theoretical and research findings on the interaction of gut microbiota, fatigue, and polyphenols. First, we outline the relationship between gut microbiota and fatigue, including changes in the gut microbiota during fatigue and how they interact with the host. Next, we describe the interactions between the gut microbiota and polyphenols in fatigue treatment (regulation of the gut microbiota by polyphenols and metabolism of polyphenols by the gut microbiota), and how the importance of potential active metabolites (such as urolithin) produced by the decomposition of polyphenols by gut microbiota is emerging. Based on the new perspective of gut microbiota, this review provides interesting insights into the mechanism of polyphenols in fatigue treatment and clarifies the potential of polyphenols as targets for anti-fatigue product development, aiming to provide a useful basis for further research and design.

Sturgeon Chondroitin Sulfate Restores the Balance of Gut Microbiota in Colorectal Cancer Bearing Mice

Chondroitin sulfate (CS) is a well-known bioactive substance with multiple biological functions, which can be extracted from animal cartilage or bone. Sturgeon, the largest soft bone animal with ~20% cartilage content, is a great candidate for CS production. Our recent study confirmed the role of sturgeon chondroitin sulfate (SCS) in reducing colorectal cancer cell proliferation and tumor formation. Here, we further studied the effect of SCS on modulating gut microbiome structure in colorectal cancer bearing mice. In this study, the transplanted tumor mice model was constructed to demonstrate that SCS can effectively halt the growth of transplanted colorectal tumor cells. Next, we showed that SCS significantly altered the gut microbiome, such as the abundance of Lactobacillales, Gastranaerophilales, Ruminiclostridiun_5 and Ruminiclostridiun_6. According to linear discriminant analysis (LDA) and abundance map analysis of the microbial metabolic pathways, the changes in microbial abundance led to an increase of certain metabolites (e.g., Phe, Tyr, and Gly). Fecal metabolome results demonstrated that SCS can significantly reduce the amount of certain amino acids such as Phe, Pro, Ala, Tyr and Leu presented in the feces, suggesting that SCS might inhibit colorectal cancer growth by modulating the gut microbiome and altering the production of certain amino acids. Our results revealed the therapeutic potential of SCS to facilitate treatment of colorectal cancer. This study provides insights into the development of novel food-derived therapies for colorectal cancer.