Metabolism of resistant starch RS3 administered in combination with Lactiplantibacillus plantarum strain 84-3 by human gut microbiota in simulated fermentation experiments in vitro and in a rat model

Characterization of a novel type 4 resistant starch from tapioca and its obesity-preventive effects through gut microbiota modulation in high-fat diet-treated mice

The rising pandemic of obesity has received significant attention. Yet, more safe and effective targeted strategies must be used to mitigate its impact on individual health and the global disease burden. While the health benefits of resistant starch (RS) are well-documented, the role of RT-90 (a phosphate-modified tapioca RS containing 90.1 % total dietary fiber) in mitigating obesity remains unknown. Accordingly, the physicochemical characteristics and protective effects of RT-90 on obesity were investigated in high-fat diet (HFD)-fed mice. Physicochemical property examinations showed that RT-90 consisted of small, round starch granules (D90: 20.69 ± 0.4 μm) with a crystalline structure, P-O-C stretching, and high peak melting temperature and enthalpy. Additionally, feeding mice with RT-90 significantly decreased body weight, improved oral glucose tolerance test (OGTT), reduced fatty liver and adipose tissue accumulation, lowered oxidative stress and inflammation by upregulating antioxidant enzymes (SOD, catalase, GPx) and anti-inflammatory cytokines (IL-4, IL-10), and enhanced fecal lipids and bile acid excretion. Notably, RT-90 administration in HFD-fed mice was associated with the inhibition of obesity-associated harmful bacteria ([Eubacterium]_xylanophilum group, Allobaculum, Clostridia_UCG-014, Dubosiella) and promotion of short-chain fatty acids (SCFAs)-producing gut flora, including Bifidobacterium, Lactobacillus, Bacteroides, and Parabacteroides, which suggests a possible mechanism by which RT-90 alters gut microbiota to attenuate obesity. These novel findings first revealed that RT-90 facilitates weight loss through its antioxidant, anti-inflammatory, and microbiota modulation abilities. This provides a promising strategy for managing overweight or obesity and holds potential for applications in developing healthy food products.

Si-Ni-San ameliorates cholestatic liver injury by favoring P. goldsteinii colonization

ETHNOPHARMACOLOGICAL RELEVANCE

Current treatment options for cholestatic liver diseases are limited, and addressing impaired intestinal barrier has emerged as a promising therapeutic approach. Si-Ni-San (SNS) is a Traditional Chinese Medicine (TCM) formula commonly utilized in the management of chronic liver diseases. Our previous studies have indicated that SNS effectively enhanced intestinal barrier function through the modulation of gut microbiota.

AIM OF THE STUDY

This study aims to verify the therapeutic effects of SNS on cholestatic liver injury, focusing on elucidating the underlying mechanism involving the gut-liver axis.

MATERIALS AND METHODS

The 16s RNA gene sequencing, non-targeted metabolomics were used to investigate the effects of SNS on the gut microbiota dysbiosis. Fecal microbiota transplantation (FMT) was conducted to identify potential beneficial probiotics underlying the therapeutic effects of SNS.

RESULTS

Our results demonstrated that SNS significantly ameliorated cholestatic liver injury induced by partial bile duct ligation (pBDL). Additionally, SNS effectively suppressed cholestasis-induced inflammation and barrier dysfunction in both the small intestine and colon. While SNS did not impact the intestinal FXR-FGF15-hepatic CYP7A1 axis, it notably improved gut microbiota dysbiosis and modulated the profile of microbial metabolites, including beneficial secondary bile acids and tryptophan derivatives. Furthermore, gut microbiota depletion experiments and FMT confirmed that the therapeutic benefits of SNS in cholestatic liver disease are dependent on gut microbiota modulation, particularly through the promotion of the growth of potential probiotic P. goldsteinii. Moreover, a synergistic improvement in cholestatic liver injury was observed with the co-administration of P. goldsteinii and SNS.

CONCLUSION

Our study underscores that SNS effectively alleviates cholestatic liver injury by addressing gut microbiota dysbiosis and enhancing intestinal barrier function, supporting its rational clinical utilization. Furthermore, we highlight P. goldsteinii as a promising probiotic candidate for the management of cholestatic liver diseases.

Secondary Metabolites Produced by the Dominant Fungus Eurotium cristatum in Liupao Tea and Their Hypolipidemic Activities by Regulating Liver Lipid Metabolism and Remodeling Gut Microbiota

Liupao tea is a postfermented dark tea with hypolipidemic activity. Research on the active substances in Liupao tea has primarily focused on those derived from the tea itself, overlooking the secondary metabolites produced by its predominant fungus, Euirotium cristatum. In this study, E. cristatum CPCC 401251, the predominant strain found in Liupao tea under investigation, was isolated and analyzed. A total of 19 representative metabolites, including prenylbenzaldehydes, diketopiperazines, and anthraquinones, were obtained from its culture. Subsequent analysis revealed the presence of multiple secondary metabolites of E. cristatum CPCC 401251 in Liupao tea. The 19 compounds significantly reduced the lipid content in free fatty acid (FFA)-stimulated hepatocyte AML-12 cells to varying degrees. Considering the content, chemical class, and biological activity of secondary metabolites from E. cristatum CPCC 401251, compounds 1, 7, and 13 were selected to detect their hypolipidemic activities and potential mechanisms in hyperlipidemia golden hamsters. Compound 1 exerted a hypolipidemic effect by activating the AMPK signaling pathway, decreasing Scd1, and improving intestinal flora. Compounds 7 and 13 played a role in the hypolipidemic activity by regulating the gene expression related to lipid synthesis and degradation, including upregulating the mRNA levels of Pparα, Hsl, and Atgl, and decreasing the mRNA level of Scd1. These findings help us understand the dominant fungus E. cristatum secondary metabolites presenting in Liupao tea and their potential hypolipidemic contributions. This work improves the understanding of the active substances in Liupao tea and highlights the health-promoting effects of microorganisms in the fermented tea.

Ameliorative effects of Bacillus subtilis C10 on alcoholic liver injury in mice

Bacillus subtilis has been reported to maintain the homeostasis of intestinal flora. In this study, a mouse model of alcoholic liver injury (ALI) was constructed to study the ameliorative effect of B. subtilis C10 on ALI and to further clarify its mechanism of action. Significant correlations between intestinal flora and biochemical indicators of ALI were found by statistical correlation analysis. Supplementation with B. subtilis C10 modulated the equilibrium of gut flora by reducing the population of detrimental bacteria while enhancing the numbers of beneficial microorganisms, which resulted in an improvement in lipid metabolism and oxidative stress in the liver. The results of RT-qPCR showed that B. subtilis C10 intervention regulated the main regulatory factors of liver lipid metabolism (PPAR-α, SREBP-1c) and interfered with Nrf-2/Ho-1 signal pathway, which in turn ameliorated alcohol-induced lipid metabolism disorder and liver peroxidation stress. In addition, liver metabonomic analysis showed that B. subtilis C10 intervention reduced the production of harmful metabolites and increased beneficial metabolites in the liver, thereby reversing the metabolic disturbances caused by excessive alcohol consumption. KEGG analysis showed that B. subtilis C10 intervention modulated liver metabolic disorders and accelerated lipid metabolism by regulating glutathione metabolic pathway, purine metabolic pathway, pantothenic acid and CoA biosynthesis pathway, ABC transporter protein pathway, and HIF-1 signaling pathway. Taken together, these findings suggest that B. subtilis C10 ameliorates ALI by modifying the structure of intestinal flora and liver metabolic pathways to attenuate alcohol-exposure-induced liver oxidative damage and lipid metabolism abnormalities. PRACTICAL APPLICATION: Bacillus subtilis C10 is an effective probiotic intervention that significantly ameliorated alcoholic liver injury in mice through the gut-liver axis. B. subtilis C10 can be used as a dietary probiotic to develop functional foods with beneficial effects for the population of excessive alcohol consumption.

Phage cocktail alleviated type 2 diabetes by reshaping gut microbiota and decreasing proinflammatory cytokines

Type 2 diabetes (T2D), a global health concern, is closely associated with the gut microbiota. Restoration of a balanced microbiota and intestinal homeostasis benefit therapy of T2D. Some special phages may selectively alter the gut microbiota without causing dysbiosis, such as MS2 and P22. However, scarcely systematic analysis of cascading effects triggered by MS2 and P22 phages on the microbiota, as well as interactions between specific gut bacteria and systemic metabolism, seriously inhibit the development of positive interventions of phages. Based on multi-omic analysis, we analyzed the intrinsic correlations among specific microbiota, their bioactive metabolites, and key indicators of T2D. We found that gavage of the MS2-P22 phage cocktail could significantly alter the gut microbiome to attenuate dysbiosis of diabetic C57BL/6 mice caused by high-fat diets (HFDs) and streptozotocin (STZ), by affecting microbial compositions as well as their metabolic pathways and metabolites, especially increasing amounts of short-chain fatty acid-producing (SCFA-producing) bacteria (e.g., Blautia and Romboutsia) and short-chain fatty acids (SCFAs). Correspondingly, a noteworthy reduction in the number of several opportunistic pathogens occurred, e.g., Candidatus Saccharimonas, Aerococcus, Oscillibacter, Desulfovibrio, and Clostridium sensu stricto 1. Synchronously, the levels of proinflammatory cytokines and lipopolysaccharide (LPS) were reduced to recover gut barrier function in T2D mice. These findings might benefit the development of a new dietary intervention for T2D based on phage cocktails. KEY POINTS: • Intestinal barrier integrity of T2D mice is improved by a phage cocktail • Negative relationship between Muribaculaceae and Corynebacterium reshaped gut microbiota • Acetate, propionate, and butyrate decreased the level of proinflammatory factors.

Enhancing optimal molecular interactions during food processing to design starch key structures for regulating quality and nutrition of starch-based foods: an overview from a synergistic regulatory perspective

Charting out personalized and/or optimized diets offers new opportunities in the field of food science, although with inherent challenges. Starch-based foods are a major component of daily energy intake in humans. In addition to being rich in starch, starchy foods also contain a multitude of bioactive substances (e.g., polyphenols, lipids). Food processing including storage affects the consistency and interactions between starch and other food components, which can affect the quality and nutritional characteristics of starch-based foods. This review describes the effects of interactions between starch and other components on the structural evolution of starch during food processing. We ponder upon how the evolution of starch molecular structure affects the quality and nutritional characteristics of starch-based foods vis-a-vis the structure-property relationship. Furthermore, we formulate best practices in processing starchy food to retain the quality and nutritional value by rationally designing starch structural domains. Interestingly, we found that inhibiting the formation of a crystalline structures while promoting the formation of short-range ordered structures and nano-aggregates can synchronously slow down its digestion and retrogradation properties, thus improving the quality and nutritional characteristics of starch-based food. This review provides theoretical guidelines for new researchers and food innovators of starch-based foods.

Flow field-flow fractionation coupled with multidetector: A robust approach for the separation and characterization of resistant starch

The unique properties of resistant starch (RS) have made it applicable in the formulation of a broad range of functional foods. The physicochemical properties of RS play a crucial role in its applications. Recently, flow field-flow fractionation (FlFFF) has attracted increasing interest in the separation and characterization of different categories of RS. In this review, an overview of the theory behind FlFFF is introduced, and the controllable factors, including FlFFF channel design, sample separation conditions, and the choice of detector, are discussed in detail. Furthermore, the applications of FlFFF for the separation and characterization of RS at both the granule and molecule levels are critically reviewed. The aim of this review is to equip readers with a fundamental understanding of the theoretical principle of FlFFF and to highlight the potential for expanding the application of RS through the valuable insights gained from FlFFF coupled with multidetector analysis.

Conjugated Linoleic Acid Ameliorates High Fat-Induced Insulin Resistance via Regulating Gut Microbiota-Host Metabolic and Immunomodulatory Interactions

Interaction between gut microbiota, host immunity and metabolism has been suggested to crucially affect the development of insulin resistance (IR). This study aims to investigate how gut microbiota, inflammatory responses and metabolism in individuals with IR are affected by the supplementation of conjugated linoleic acid (CLA) and how this subsequently affects the pathophysiology of IR by using a high-fat diet-induced IR mouse model. Serum biochemical indices showed that 400 mg/kg body weight of CLA effectively attenuated hyperglycemia, hyperlipidemia, glucose intolerance and IR, while also promoting antioxidant capacities. Histomorphology, gene and protein expression analysis revealed that CLA reduced fat deposition and inflammation, and enhanced fatty acid oxidation, insulin signaling and glucose transport in adipose tissue or liver. Hepatic transcriptome analysis confirmed that CLA inhibited inflammatory signaling pathways and promoted insulin, PI3K-Akt and AMPK signaling pathways, as well as linoleic acid, arachidonic acid, arginine and proline metabolism. Gut microbiome analysis further revealed that these effects were highly associated with the enriched bacteria that showed positive correlation with the production of short-chain fatty acids (SCFAs), as well as the improved SCFAs production simultaneously. This study highlights the therapeutic actions of CLA on ameliorating IR via regulating microbiota-host metabolic and immunomodulatory interactions, which have important implications for IR control.

Structure properties of Canna edulis RS3 (double enzyme hydrolysis) and RS4 (OS-starch and cross-linked starch): Influence on fermentation products and human gut microbiota

This study investigated the in vitro fermentation characteristics of different structural types of Canna edulis resistant starch (RS). RS3 was prepared through a double enzyme hydrolysis method, and RS4 (OS-starch and cross-linked starch) was prepared using octenyl succinic anhydride and sodium trimetaphosphate/sodium tripolyphosphate, respectively. The RS3 and RS4 samples were structurally analyzed using scanning electron microscopy, Fourier-transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction analysis. This was followed by in vitro fermentation experiments. The results revealed microstructure differences in the two groups of starch samples. Compared to native starch, RS3 and RS4 exhibited a lower degree of order and endothermic energy, with lower crystallinity (RS3: 29.59 ± 1.11 %; RS4 [OS-starch]: 28.01 ± 1.32 %; RS4 [cross-linked starch]: 30.44 ± 1.73 %) than that in native starch (36.29 ± 0.89 %). The RS content was higher in RS3 (63.40 ± 2.85 %) and RS4 (OS-starch: 71.21 ± 1.28 %; cross-linked starch: 74.33 ± 0.643 %) than in native starch (57.71 ± 2.95 %). RS3 and RS4 exhibited slow fermentation rates, promoting the production of short-chain fatty acids. RS3 and cross-linked starch significantly increased the production of acetate and butyrate. Moreover, RS3 significantly promoted the abundance of Lactobacillus, while OS-starch and cross-linked starch significantly enhanced the abundance of Dorea and Coprococcus, respectively. Hence, the morphological structure and RS content of the samples greatly influenced the fermentation rate. Moreover, the different varieties of RS induced specific gut microbial regulation. Hence, they show potential applications in functional foods for tailored gut microbiota management.

Malus baccata (Linn.) Borkh polyphenols-loaded nanoparticles ameliorate intestinal health by modulating intestinal function and gut microbiota

The aim of this study was to construct the nanoparticles based on Hohenbuehelia serotina polysaccharides and mucin for encapsulation of the polyphenols from Malus baccata (Linn.) Borkh (MBP-MC-HSP NPs), and investigate their effects on intestinal function and gut microbiota in mice. The results showed that MBP-MC-HSP NPs did not have any toxic and side effect by determining organ indexes and hematological parameters. The colonic index, colonic length as well as colonic histology were significantly improved by treatment of MBP-MC-HSP NPs. Moreover, MBP-MC-HSP NPs could increase the fecal moisture (84.71 %) and accelerate the intestinal peristalsis (77.87 %), thus reducing the defecation time (1.68 h) of mice at certain extent. Through production of acetic acid, propionic acid and n-butyric acid, MBP-MC-HSP NPs remarkably decreased the pH of colonic feces to maintain intestinal health. 16S rRNA sequencing analysis showed that MBP-MC-HSP NPs could improve the abundances of Lactobacillus, Butyicicoccus and Ruminococcus and suppress the richness of Prevotella, Bifidobacterium and Desulfovibrio, thereby optimizing the structure and composition of gut microbiota. Furthermore, the metabolic profiles of gut microbiota were influenced by MBP-MC-HSP NPs based on prediction of KEGG and COG databases. Overall, this study suggests that MBP-MC-HSP NPs can be developed and utilized as probiotics in the nutritional food field.

Effects of probiotics in patients with morbid obesity undergoing bariatric surgery: a systematic review and meta-analysis

BACKGROUND

Probiotics are commonly used after bariatric surgery. However, uncertainty remains regarding their effects. The purpose of this systematic review was to assess the effect of probiotics in patients with morbid obesity undergoing bariatric surgery.

METHODS

PubMed, Cochrane Library, Embase, Science Direct, and Web of Science were searched from inception to April 4, 2023. No language restrictions were applied. Relevant randomized controlled trials and controlled clinical trials were included. We used the aggregated data extracted from the trials and assessed the heterogeneity. When severe heterogeneity was detected, a random effect model was used. All stages of the review were done by independent authors.

RESULTS

We screened 2024 references and included 11 randomized controlled trials and controlled clinical trials. Compared with the protocol groups, probiotics showed significant effects on regulating aspartate amino transferase level (MD = -4.32 U/L; 95% CI [-7.10, -1.53], p = 0.002), triglycerides (MD = -20.16 mg/dL; 95% CI [-34.51, -5.82], p = 0.006), weight (MD = -1.99 kg; 95% CI [-3.97, -0.01], p = 0.05), vitamin B12 (MD = 2.24 pg/dL; 95% CI [-0.02, 4.51], p = 0.05), dietary energy (MD = -151.03 kcal; 95% CI [-215.68, -86.37], p < 0.00001), dietary protein (MD = -4.48 g/day, 95% CI [-8.76, -0.20], p = 0.04), dietary carbohydrate (MD = -34.25 g/day, 95% CI [-44.87, -23.62], p < 0.00001), and dietary fiber (MD = -2.17 g/day, 95% CI [-3.21, -1.14], p < 0.0001). There were no severe side effects related to probiotics.

CONCLUSIONS

Our meta-analysis suggested that probiotics may delay the progression of liver function injury, improve lipid metabolism, reduce weight, and reduce food intake, although the effects on other indicators were insignificant. Probiotics may be helpful for patients undergoing bariatric surgery. The review was registered on PROSPERO (International prospective register of systematic reviews): CRD42023407970. No primary source of funding.

Mechanism of Lactiplantibacillus plantarum regulating Ca2+ affecting the replication of PEDV in small intestinal epithelial cells

Porcine epidemic diarrhea virus (PEDV) mainly invades the small intestine and promotes an inflammatory response, eventually leading to severe diarrhea, vomiting, dehydration, and even death of piglets, which seriously threatens the economic development of pig farming. In recent years, researchers have found that probiotics can improve the intestinal microenvironment and reduce diarrhea. At the same time, certain probiotics have been shown to have antiviral effects; however, their mechanisms are different. Herein, we aimed to investigate the inhibitory effect of Lactiplantibacillus plantarum supernatant (LP-1S) on PEDV and its mechanism. We used IPEC-J2 cells as a model to assess the inhibitory effect of LP-1S on PEDV and to further investigate the relationship between LP-1S, Ca2+, and PEDV. The results showed that a divalent cation chelating agent (EGTA) and calcium channel inhibitors (Bepridil hydrochloride and BAPTA-acetoxymethylate) could inhibit PEDV proliferation while effectively reducing the intracellular Ca2+ concentration. Furthermore, LP-1S could reduce PEDV-induced loss of calcium channel proteins (TRPV6 and PMCA1b), alleviate intracellular Ca2+ accumulation caused by PEDV infection, and promote the balance of intra- and extracellular Ca2+ concentrations, thereby inhibiting PEDV proliferation. In summary, we found that LP-1S has potential therapeutic value against PEDV, which is realized by modulating Ca2+. This provides a potential new drug to treat PEDV infection.

Fucoxanthin Ameliorates Sepsis via Modulating Microbiota by Targeting IRF3 Activation

To improve patient survival in sepsis, it is necessary to curtail exaggerated inflammatory responses. Fucoxanthin (FX), a carotenoid derived from brown algae, efficiently suppresses pro-inflammatory cytokine expression via IRF3 activation, thereby reducing mortality in a mouse model of sepsis. However, the effects of FX-targeted IRF3 on the bacterial flora (which is disrupted in sepsis) and the mechanisms by which it impacts sepsis development remain unclear. This study aims to elucidate how FX-targeted IRF3 modulates intestinal microbiota compositions, influencing sepsis development. FX significantly reduced the bacterial load in the abdominal cavity of mice with cecal ligation and puncture (CLP)-induced sepsis via IRF3 activation and increased short-chain fatty acids, like acetic and propionic acids, with respect to their intestines. FX also altered the structure of the intestinal flora, notably elevating beneficial Verrucomicrobiota and Akkermansia spp. while reducing harmful Morganella spp. Investigating the inflammation-flora link, we found positive correlations between the abundances of Morganella spp., Proteus spp., Escherichia spp., and Klebsiella spp. and pro-inflammatory cytokines (IL-6, IL-1β, and TNF-α) induced by CLP. These bacteria were negatively correlated with acetic and propionic acid production. FX alters microbial diversity and promotes short-chain fatty acid production in mice with CLP-induced sepsis, reshaping gut homeostasis. These findings support the value of FX for the treatment of sepsis.

A High-Fat, High-Cholesterol Diet Promotes Intestinal Inflammation by Exacerbating Gut Microbiome Dysbiosis and Bile Acid Disorders in Cholecystectomy

Patients with post-cholecystectomy (PC) often experience adverse gastrointestinal conditions, such as PC syndrome, colorectal cancer (CRC), and non-alcoholic fatty liver disease (NAFLD), that accumulate over time. An epidemiological survey further revealed that the risk of cholecystectomy is associated with high-fat and high-cholesterol (HFHC) dietary intake. Mounting evidence suggests that cholecystectomy is associated with disrupted gut microbial homeostasis and dysregulated bile acids (BAs) metabolism. However, the effect of an HFHC diet on gastrointestinal complications after cholecystectomy has not been elucidated. Here, we aimed to investigate the effect of an HFHC diet after cholecystectomy on the gut microbiota-BA metabolic axis and elucidate the association between this alteration and the development of intestinal inflammation. In this study, a mice cholecystectomy model was established, and the levels of IL-Iβ, TNF-α, and IL-6 in the colon were increased in mice fed an HFHC diet for 6 weeks. Analysis of fecal BA metabolism showed that an HFHC diet after cholecystectomy altered the rhythm of the BA metabolism by upregulating liver CPY7A1, CYP8B1, and BSEP and ileal ASBT mRNA expression levels, resulting in increased fecal BA levels. In addition, feeding an HFHC diet after cholecystectomy caused a significant dysbiosis of the gut microbiota, which was characterized by the enrichment of the metabolic microbiota involved in BAs; the abundance of pro-inflammatory gut microbiota and related pro-inflammatory metabolite levels was also significantly higher. In contrast, the abundance of major short-chain fatty acid (SCFA)-producing bacteria significantly decreased. Overall, our study suggests that an HFHC diet after cholecystectomy promotes intestinal inflammation by exacerbating the gut microbiome and BA metabolism dysbiosis in cholecystectomy. Our study also provides useful insights into the maintenance of intestinal health after cholecystectomy through dietary or probiotic intervention strategies.