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Dietary Supplementation of Glutamate Alleviates LPS-Induced Intestinal Injury Associated with m6A Modification of SLC10A2 in Weaned Piglets
by
Zhending Gan
1, 
Jiawei He
1,
Qiyue Jin
1,
Qiuqin Ma
2,
Chuanlong Wang
3,* and
Xiang Zhong
1,4,5,6,*
1
College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China
2
Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Crop and Livestock Integration, Ministry of Agriculture and Rural Affairs, Nanjing 210014, China
3
College of Animal Science and Technology, Yangzhou University, Yangzhou 225000, China
4
Institute of Animal Nutrition and Health Industry, Anyou Biotechnology, Nanjing Agricultural University, Nanjing 210095, China
5
Natural Plant and Animal Health Innovation Institute, NJAU-Cohoo Biotechnology, Nanjing Agricultural University, Nanjing 210095, China
6
State Key Laboratory of Meat Quality Control and Cultured Meat Development, Nanjing Agricultural University, Nanjing 210095, China
*
Authors to whom correspondence should be addressed.
Animals 2026, 16(18), 2854; https://doi.org/10.3390/ani16182854
Submission received: 12 August 2026
/
Revised: 8 September 2026
/
Accepted: 9 September 2026
/
Published: 10 September 2026
(This article belongs to the Special Issue Feeding Strategies to Optimize Growth and Reduce Waste in Pigs)
Simple Summary
Weaning stress and acute inflammatory challenges can compromise intestinal barrier function and bile acid homeostasis in piglets. Glutamate is a key energy substrate and functional amino acid for intestinal epithelial cells, but its epitranscriptomic role in intestinal inflammation remains incompletely understood. This study examined whether dietary glutamate supplementation is associated with altered N6-methyladenosine (m6A) modification of SLC10A2 and bile acid signaling in an acute LPS challenge model in weaned piglets, with supporting validation in IPEC-J2 cells. LPS challenge disrupted ileal morphology, triggered TLR4/NF-κB-driven inflammation and disturbed bile acid distribution. Glutamate supplementation was associated with restored mucosal integrity, suppressed TLR4/NF-κB signaling, and promoted ileal bile acid reabsorption. Glutamate-derived α-ketoglutarate may support the expression of m6A demethylases FTO and ALKBH5, lowering m6A modification of SLC10A2 and limiting YTHDF2-mediated SLC10A2 mRNA degradation, which may in turn preserve FXR expression. In vitro assays supported these observations. Collectively, these findings provide evidence for a glutamate–α-KG–m6A–SLC10A2–FXR axis that may contribute to intestinal protection under acute inflammatory stress, offering a potential epigenetic target for nutritional intervention in stressed piglets.
Abstract
Acute inflammatory challenge can impair intestinal barrier function and bile acid homeostasis in weaned piglets. Glutamate serves as an important energy substrate and functional amino acid for intestinal epithelial cells, yet the epitranscriptomic mechanisms underlying its potential protective effects remain poorly defined. This study investigated whether dietary glutamate supplementation is associated with m6A-dependent regulation of SLC10A2 and bile acid signaling in weaned piglets subjected to an acute LPS challenge, with supporting validation in IPEC-J2 cells. LPS challenge (100 μg/kg body weight) impaired ileal morphological structure, activated the TLR4/NF-κB signaling pathway, and aggravated intestinal inflammatory responses in piglets. In contrast, glutamate supplementation was associated with restored ileal mucosal morphology, up-regulated expression of intestinal tight junction proteins, and suppressed TLR4/NF-κB pathway activation. Further metabolomic analysis indicated that LPS stimulation and glutamate intervention altered ileal bile acid metabolism: LPS decreased total bile acid (TBA) content in ileal tissue while increasing TBA accumulation in ileal chyme, whereas glutamate treatment partially reversed this pattern, by elevating ileal tissue TBA and reducing chyme TBA, suggesting a facilitatory effect of glutamate on intestinal bile acid reabsorption. Glutamate supplementation was also associated with increased ileal ASBT (SLC10A2) and FXR (NR1H4) expression. The SLC10A2 transcript exhibited detectable m6A modification; glutamate supplementation rescued the LPS-induced downregulation of m6A demethylases FTO and ALKBH5, which was associated with reduced global and SLC10A2-specific m6A modification. In vitro experiments in IPEC-J2 cells suggested that inhibition of FTO or glutamate dehydrogenase attenuated the effects of glutamate on m6A modification and SLC10A2 expression, and that YTHDF2 may contribute to the degradation of hyper-m6A-modified SLC10A2 mRNA. Glutamate-derived α-KG may serve as a cofactor supporting demethylase expression and activity after LPS stimulation. Collectively, these findings suggest that glutamate may alleviate LPS-induced intestinal inflammation in weaned piglets through a pathway involving α-KG-dependent maintenance of m6A demethylase expression, reduced m6A modification of SLC10A2, and preserved ASBT/FXR signaling. This study provides evidence for a nutritional–epitranscriptomic axis that may contribute to intestinal protection under acute inflammatory stress.
Keywords:
glutamate; weaned piglets; m6A modification; SLC10A2/ASBT; bile acid metabolism; FXR
