Detection of typical indigenous gut bacteria related to kanpyo Lagenaria siceraria var. hispida powder in murine caecum and human faecal cultures.

Kanpyo (KP) is an edible dried product produced by peeling the fruit of the gourd Lagenaria siceraria var. hispida; it is used in the traditional Japanese cuisine. The health functionality of KP due to its rich dietary fibre is expected to include a possible combined effect of KP-responsive indigenous gut bacteria (KP-RIB). However, its effect on the gut microbiota is unclear. To determine the effects of the KP on the gut microbiota and their host, Institute of Cancer Research mice were fed a high-sucrose diet containing no fibre (NF) or 5% (w/w) KP for 14 days, and their caecal microbiota was analysed by 16S rRNA (V4) amplicon sequencing. Higher faecal frequency and weight and lower spleen weight and spleen tumour necrosis factor-α levels were observed in KP-fed mice than in NF-fed mice (p < 0.05). KP increased and decreased the abundance of short-chain fatty acid producer Lachnospiraceae and obesity-inflammation related Allobaculum species, respectively. In the case of human faecal cultures, stool samples from five healthy volunteers were inoculated and incubated at 37 °C for 24 h anaerobically; 3.2% (w/v) KP suppressed putrefactive compounds (indole, phenol, and ammonia). KP increased butyrate-producer Faecalibacterium, acetate/lactate-producer Bifidobacterium, and Lachnospira. Furthermore, KP cultures showed high antioxidant and RAW264.7 macrophage cell activation capacities. These results suggest that KP-RIB and KP intake may synergistically affect host health. However, further studies are required to clarify the synergistic effects of KP and KP-RIB.

Effects of Sichuan pepper (huajiao) powder on disease activity and caecal microbiota of dextran sodium sulphate-induced inflammatory bowel disease mouse model.

BACKGROUND: Sichuan pepper [Zanthoxylum bungeanum; huajiao (HJ)] is a widely used spice in China and has better antioxidative, anti-glycation, and bile acid-lowering properties than cumin and coriander seeds. HJ affects inflammation-related cytokines and caecal microbiota in mice fed a low-fibre and high-sucrose diet. METHODS AND RESULTS: To determine the ameliorative effect of HJ on inflammatory bowel disease, C57BL/6 mice were divided into three groups and fed distilled water (control) or 3% (w/v) dextran sodium sulphate (DSS) in drinking water with normal chow containing 0% or 5% (w/w) HJ powder for seven days. After 6 days of feeding, diarrhoea, decreased body weight, and blood in faeces were observed in the DSS group. DSS treatment increased the spleen weight and damaged the colon tissue. These inflammatory indices were inhibited by HJ treatment. Amplicon sequencing of the 16S rDNA (V4) gene of the caecal content revealed a decrease in the alpha diversity (Simpson index D) in the DSS treatment group compared to the control group. The abundance of caecal Desulfovibrio, an inflammation-related genus, was higher and the caecal Lachnospiraceae and Bacteroides levels were lower in the DSS-treated mice than those in the control mice. However, HJ suppressed the DSS-induced changes in the caecal microbiota. CONCLUSION: HJ intake contributes to the reduction in inflammation and maintenance of the gut microbiota. However, the strong antioxidant properties of phenolic compounds and fermentability of water-soluble dietary fibres in HJ and their relationship with other functional properties warrant further investigation.

The effect of Sichuan pepper on gut microbiota in mice fed a high-sucrose and low-dietary fibre diet.

Sichuan pepper (Zanthoxylum bungeanum, HJ), a spice widely used in China, has antioxidative, anti-inflammatory, antibacterial, and anti-obesity properties. In this study, to confirm the value of HJ as a functional food, the in vitro antioxidant and bile acid-lowering capacities, as well as the effects on caecal microbiota, were compared with those of cumin (Cuminum cyminum, CM) and coriander (Coriandrum sativum, CR) seeds in Institute of Cancer Research (ICR) mice fed a high-sucrose and low-dietary fibre diet. The total phenolic content, superoxide anion radical-scavenging capacity, and Fe-reducing power of the HJ aqueous solution were higher than those of CM and CR (p < 0.05). The bile acid (taurocholic, glycocholic, and deoxycholic acids)-lowering capacity of the HJ suspension was also higher than those of CM and CR. Compared with mice fed a control diet (no fibre, NF), caecal Lactobacillus gasseri- and Muribaculum intestinale-like bacteria were higher in mice fed a diet containing 5% (w/w) of CM, CR, or HJ for 14 days. Bifidobacterium pseudolongum-, Lactobacillus murinus/animalis-, and Faecalibaculum rodentium-like bacteria were significantly increased, while Desulfovibrio-like bacteria were significantly decreased in the HJ group. In addition, CM and HJ may benefit specific metabolic functions of gut microbiota, such as starch, sucrose, and tyrosine metabolism. The tumour necrosis factor (TNF-α) concentration in the spleen tissue of ICR mice was decreased by the intake of spices. However, there were no changes in interleukin-2 (IL-2) and IL-10 levels in HJ fed mice. These results suggested that HJ has potential as a functional food related to gut microbiota. KEY POINTS: • Bididobacterium and Faecalibaculum in mice gut microbiota are increased by Sichuan pepper (HJ). • Desulfovibrionaceae, an inflammatory LPS producer, in mice gut microbiota is decreased by HJ. • HJ decreases pro-inflammatory TNF both in murine spleen tissue and in vitro macrophages.

Detection of indigenous gut bacteria related to red chilli pepper (Capsicum annuum) in murine caecum and human faecal cultures.

BACKGROUND: Red chilli pepper (Capsicum annuum; RP) is a popular spice containing the active compound capsaicin. Indigenous gut bacteria and metabolism can affect host health. The functions of capsaicin, including the regulation of metabolic health and anti-oxidant properties, may be correlated with the gut microbiota. METHODS: To identify indigenous gut bacteria that are responsive to RP, Institute of Cancer Research mice fed a diet with no fibre or with 5% (w/w) RP for 14 days. Additionally, human stool samples collected from four healthy volunteers were incubated without (control) or with 2% (w/v) RP at 37 °C for 24 h. Microbiota in murine caecal samples and human faecal cultures were analysed using 16S rRNA (V4) amplicon sequencing. RESULTS: Compared with the microbiota in mice fed no-fibre diets, Lachnospiraceae spp.-, Muribaculaceae spp.-, and Phacaeicola vulgatus-like bacteria were defined as murine RP-responsive indigenous gut bacteria (RP-RIB). In the human faecal cultures, acetate and propionate levels were higher in RP cultures than in the control cultures. Subdoligranulum spp.-, Blautia spp.-, Faecalibacterium prausnitzii-, P. vulgatus-, and Prevotella copri-like bacteria were defined as human RP-RIB. Compared with control culture Fe-reducing power was increased in the culture with RP. CONCLUSION: RP increases the amount of short-chain fatty acid-producing bacteria and beneficial gut bacteria in mouse and human faecal cultures. Overall, RP could have a positive effect on the host by altering the gut microbiota.

In vitro antioxidant, anti-glycation, and bile acid-lowering capacity of peanut milk fermented with Lactiplantibacillus plantarum Kinko-SU4.

Plant-based milk-like products from soybeans and other legumes and nuts have been explored worldwide, owing to their nutritional and functional characteristics. This study was conducted to develop new functional food materials from peanut (Arachis hypogaea) milk (PM) with desirable health functions to mitigate lifestyle and age-related diseases. The antioxidant, anti-glycation and bile acid-lowering properties of PM fermented with lactic acid bacteria Lactiplantibacillus plantarum Kinko-SU4 (FPM) were determined in vitro. L. plantarum Kinko-SU4 lowered the pH level from 6.4 to 4.3, 3.9, and 3.7 at 10, 24, and 48 h, respectively. The lactic acid concentration was 4.4 mg/mL after 48 h of incubation. The starter degraded the dissolved proteins in PM, including Ara h 1, one of the peanut allergens. Although the total phenolic content was 36% lower in FPM than in unfermented PM, O2 - radical-scavenging capacity was high in FPM. Anti-glycation in a bovine serum albumin-fructose model and the bile acid-lowering capacities of PM were distinctly increased following fermentation. The result of this study infers that PM fermented with L. plantarum Kinko-SU4 can be considered a desirable food material to prevent and ameliorate chronic lifestyle diseases, particularly in the elderly.