Inclusion of Soluble Fiber During Gestation Regulates Gut Microbiota, Improves Bile Acid Homeostasis, and Enhances the Reproductive Performance of Sows

Gut-Microbiota-Driven Lipid Metabolism: Mechanisms and Applications in Swine Production

Background/Objectives: The gut microbiota plays a pivotal role in host physiology through metabolite production, with lipids serving as essential biomolecules for cellular structure, metabolism, and signaling. This review aims to elucidate the interactions between gut microbiota and lipid metabolism and their implications for enhancing swine production. Methods: We systematically analyzed current literature on microbial lipid metabolism, focusing on mechanistic studies on microbiota-lipid interactions, key regulatory pathways in microbial lipid metabolism, and multi-omics evidence (metagenomic/metabolomic) from swine models. Results: This review outlines the structural and functional roles of lipids in bacterial membranes and examines the influence of gut microbiota on the metabolism of key lipid classes, including cholesterol, bile acids, choline, sphingolipids, and fatty acids. Additionally, we explore the potential applications of microbial lipid metabolism in enhancing swine production performance. Conclusions: Our analysis establishes a scientific framework for microbiota-based strategies to optimize lipid metabolism. The findings highlight potential interventions to improve livestock productivity through targeted manipulation of gut microbial communities.

Personalized Microbial Fingerprint Associated with Differential Glycemic Effects of a Whole Grain Rye Intervention on Chinese Adults

SCOPE

This study aims to identify the gut enterotypes that explain differential responses to intervention with whole grain rye by proposing an "enterotype - metabolic" model.

METHODS AND RESULTS

A 12-week randomized controlled trial is conducted in Chinese adults, with 79 subjects consuming whole grain products with fermented rye bran (FRB) and 77 consuming refined wheat products in this exploratory post-hoc analysis. Responders or non-responders are identified according to whether blood glucose decreased by more than 10% after rye intervention. Compared to non-responders, responders in FRB have higher baseline Bacteroides (p < 0.001), associated with reduced blood glucose (p < 0.001), increased Faecalibacterium (p = 0.020) and Erysipelotrichaceae_UCG.003 (p = 0.022), as well as deceased 7β-hydroxysteroid dehydrogenase (p = 0.033) after intervention. The differentiated gut microbiota and metabolites between responders and non-responders after intervention are enriched in aminoacyl-tRNA biosynthesis.

CONCLUSION

The work confirms the previously suggested importance of microbial enterotypes in differential responses to whole grain interventions and supports taking enterotypes into consideration for improved efficacy of whole grain intervention for preventing type 2 diabetes. Altered short-chain fatty acids and bile acid metabolism might be a potential mediator for the beneficial effects of whole grain rye on glucose metabolism.

Bamboo fiber improves piglet growth performance by regulating the microbial composition of lactating sows and their offspring piglets

Introduction

Feeding bamboo powder is a kind of fiber raw material mainly composed of insoluble dietary fiber (IDF). In this study, IDF-based rice husk meal and feeding bamboo powder were used to compare the effects of bamboo fiber on fecal microflora and the performance of lactating sows and their offspring piglets.

Methods

Thirty healthy crossbred gilts (Yorkshire × Landrace) at day 105 of gestation were randomly allocated into three groups: CON, TRE1 supplemented with 2% BBF1 (feeding bamboo powder), and TRE2 supplemented with 2% BBF2 (99% feeding bamboo powder +1% bamboo fiber polymer material). The reproductive performance, serum indexes, and fecal microbiota of sows and piglets were analyzed. The results showed that, compared with CON, the average feed intake of sows in TRE1 during the second week of lactation was significantly increased by 21.96% (p < 0.05), the average daily gain (ADG) per litter in TRE1 on 11-21 days and 3-21 days of lactation was significantly increased by 50.68 and 31.61%, respectively (p < 0.05), and the serum triglyceride content of sows in TRE1 on the 21st day of lactation was significantly increased (p < 0.05). The 16S rRNA analysis showed that dietary bamboo fiber significantly increased the fecal microbial richness index Ace, Chao, and Sobs of sows (p < 0.05) and tended to increase the Sobs index of suckling piglets on day 21 (p < 0.10). Compared with CON, BBF1 supplementation significantly decreased the abundance of Christensenellaceae_R-7_group in feces of sows on days 7 and 21 after delivery (p < 0.05), while BBF2 decreased the genera Christensenellaceae_R-7_group on days 7 (p < 0.10) and 21 (p < 0.05) after delivery. Spearman correlation analysis showed that the abundance of Phascolarctobacterium in the feces of piglets on the 21st day after delivery was significantly positively correlated with diarrhea rate and significantly negatively correlated with ADG per litter, day 21 litter weight, and 3- to 21-day survival rate. In contrast, Christensenellaceae_R-7_group was significantly negatively correlated with diarrhea rate and positively correlated with ADG per litter.

Discussion

These results indicated that maternal BBF1 supplementation improved the litter weight gain of suckling piglets, which was associated with the improvement of diversity and structure of the fecal microbiota in the piglets.

Importance of dietary supplementation of soluble and insoluble fibers to sows subjected to high ambient temperatures during late gestation and effects on lactation performance

Heat stress adversely affects sows' performance, which can be improved by applying proper nutritional strategies. This study was conducted to investigate the interactive effects of dietary fiber levels and sources on sows' reproductive performance, metabolic response during gestation, and the carry-over influence on litter performance in the lactation period during heat stress (average room temperature of 27.1 °C). Fifty-four multiparous sows (Landrace × Yorkshire; initial body weight of 236.3 ± 16 kg; 2, 3 and 4 parities) at d 90 of gestation were assigned to a 2 × 3 factorial arrangement (9 sows/treatment), involving 2 dietary fiber levels (4.5% and 6% crude fiber) and 3 dietary fiber sources (wheat bran [WB], palm kernel meal [PK], and beet pulp [BP]). Sows fed the BP diet had highest (P < 0.01) feed intake and constipation index and lowest (P < 0.01) farrowing duration. Piglet weight (P = 0.041) and litter weight (P < 0.01) at weaning were higher in sows in the BP treatment compared to PK treatment. Sows in the BP treatment showed the greatest (P < 0.01) digestibility of crude protein and neutral detergent fiber. The fecal concentration of acetate was the lowest (P < 0.01) in the PK treatment. Total short-chain fatty acid production was increased in the WB and BP treatments compared with the PK. Sows in the BP treatment showed the lowest (P = 0.036) hair cortisol. The blood insulin concentration of sows was higher (P = 0.026) in the high fiber (6%) treatment compared with the low fiber (4.5%) treatment at 90 min and 120 min after the meal. The concentration of phthalic acid, succinic acid, phenylethylamine, hydrocinnamic acid, iron, linoleic acid, glycerol, ketone, and formamide were increased (P < 0.05) in the BP treatment compared with the WB. The BP treatment with high soluble fiber content improved the constipation index, farrowing duration, and litter performance, while high insoluble fibers increased sows comfort and reduced stress factors including respiratory rate and rectal temperature. Therefore, both soluble and insoluble sources of fiber are necessary to be added to the diet of gestating sows.

Enhancing milk quality and modulating rectal microbiota of dairy goats in starch-rich diet: the role of bile acid supplementation

BACKGROUND

Diets rich in starch have been shown to increase a risk of reducing milk fat content in dairy goats. While bile acids (BAs) have been used as a lipid emulsifier in monogastric and aquatic animals, their effect on ruminants is not well understood. This study aimed to investigate the impact of BAs supplementation on various aspects of dairy goat physiology, including milk composition, rumen fermentation, gut microbiota, and BA metabolism.

RESULTS

We randomly divided eighteen healthy primiparity lactating dairy goats (days in milk = 100 ± 6 d) into two groups and supplemented them with 0 or 4 g/d of BAs undergoing 5 weeks of feeding on a starch-rich diet. The results showed that BAs supplementation positively influenced milk yield and improved the quality of fatty acids in goat milk. BAs supplementation led to a reduction in saturated fatty acids (C16:0) and an increase in monounsaturated fatty acids (cis-9 C18:1), resulting in a healthier milk fatty acid profile. We observed a significant increase in plasma total bile acid concentration while the proportion of rumen short-chain fatty acids was not affected. Furthermore, BAs supplementation induced significant changes in the composition of the gut microbiota, favoring the enrichment of specific bacterial groups and altering the balance of microbial populations. Correlation analysis revealed associations between specific bacterial groups (Bacillus and Christensenellaceae R-7 group) and BA types, suggesting a role for the gut microbiota in BA metabolism. Functional prediction analysis revealed notable changes in pathways associated with lipid metabolism, suggesting that BAs supplementation has the potential to modulate lipid-related processes.

CONCLUSION

These findings highlight the potential benefits of BAs supplementation in enhancing milk production, improving milk quality, and influencing metabolic pathways in dairy goats. Further research is warranted to elucidate the underlying mechanisms and explore the broader implications of these findings.

Effects from supplementary feeding of bamboo powder in perinatal period on farrowing process, serum biochemical indexes, and fecal microbes of sows and offspring piglets

Introduction

This study was conducted to explore the effects of supplementary feeding of bamboo powder on the physical parameters of sows during the perinatal period of 7 days ± in parturition, including farrow duration, serum biochemical indexes, fecal physicochemical indexes, and microbial flora.

Methods

Thirty pregnant sows were randomly divided into three groups: the control group was fed a basal diet, TRE1 group and TRE2 group were fed a basal diet supplemented with 30 g d^-1 and 60 g d^-1 bamboo powder, respectively. Multiple parameters of sows and offspring piglets were determined.

Results

The contents of serum total cholesterol and triglyceride of sows in TRE2 group were significantly lower than those in the control group. The contents of serum malondialdehyde of sows in TRE2 and TRE1 groups were significantly lower than that in control group. The water content of sow feces in TRE2 group was significantly higher than that in control group, and the pH values of sows in TRE2 and TRE1 groups were significantly higher than that in control group. The richness index (Chao) of sow fecal bacterial community in TRE2 group was significantly lower than that of the control group, and the Ace and Sobs indexes tended to be lower than those of the control group. At the phylum level, the relative abundance of Actinobacteriota in the feces of sows in TRE2 group was significantly lower than that of the control group, while that of Fusobacteriota in the feces of suckling piglets in TRE2 group tended to be lower than that of the control group. At the genus level, among the Top10 dominant bacteria, the relative abundance of Tissierella in the feces of sows in TRE2 group was significantly lower than that of the control group while that of Fusobacterium in the feces of suckling piglets in TRE2 group tended to be lower than that of the control group. The relative abundance of Clostridium_sensu_stricto_1, Terrisporobacter, Turicibacter, and Tissierella in the feces of sows in TRE2 group was significantly lower than that of TRE1 group (p < 0.05), while Lactobacillus tended to be higher than that of TRE1 group (p < 0.10).

Discussion

The results suggested that supplementary feeding 60 g d^-1 bamboo powder could increase the water content in the feces of sows, reduce the oxidative damage, and tend to reduce the relative abundance of opportunistic pathogenic Fusobacterium for suckling piglets, while it reduced the fecal microbial diversity of sows.

Metabolic Responses of Dietary Fiber during Heat Stress: Effects on Reproductive Performance and Stress Level of Gestating Sows

Heat stress is an important issue, and the addition of fiber to the diet is an option in modifying intestinal health. This study evaluated the effect of acid detergent fiber (ADF) levels on reproductive performance, intestinal integrity, and metabolism of gestating sows, and its carry-over effect on the lactation period during heat stress. The diets included 4.3% (Low fiber; LF), 5.4% (Medium fiber; MF), and 6.5% (High fiber; HF) ADF. Sows fed the HF diet showed a lower respiratory rate, hair cortisol concentration, and farrowing duration compared with the LF treatment. The HF diet increased the pyruvate, citrate cycle, glyoxylate, dicarboxylate, and thiamine metabolism compared with the MF. The concentration of acetate and total short-chain fatty acids were increased in the sows fed the HF diet. The gene expression of glucose transporter 3 and glucose transporter 4 was increased in the HF treatment. The gene expression of heat shock protein 70 was decreased in the HF treatment. The HF diet during gestation increased feed intake, constipation index, piglet weight, and litter weight compared with the LF. Sows in the LF treatment showed the greatest digestibility of crude protein and the lowest digestibility of ADF. In conclusion, a 6.5% ADF level is recommended for gestating sows during heat stress.

Research on Gut Microbiota-Derived Secondary Bile Acids in Cancer Progression

The interaction between gut microbiota-derived metabolites and the body plays a significant role in the occurrence and development of cancer. Secondary bile acids (BAs) are the important products produced from gut microbial fermentation of primary BAs, mainly deoxycholic acid (DCA) and lithocholic acid (LCA). In the gut, they can influence the structure of the microbial communities. Several studies have demonstrated that secondary BAs, as signaling molecules, can activate a variety of signaling pathways. They can inhibit the apoptosis of cancer cells, induce the progression of cancer cell cycles, enhance the ability of metastasis and invasion of cancer cells, and promote the transformation of cells into cancer stem cells (CSCs). Moreover, secondary BAs promote cancer by regulating the function of immune cells. Therefore, targeted manipulation of gut microbial and secondary BAs has the potential to be developed as for treatment and prevention of various cancers.