About

Haopeng Xiao is a Principal Investigator and Assistant Professor in the Department of Biochemistry at Stanford University, as well as a member of the Stanford Cancer Institute. His research focuses on understanding the molecular mechanisms underlying cancer biology and biochemistry, contributing to the development of targeted therapies and diagnostic tools. With a background that includes a B.S. from Vanderbilt University, his work integrates biochemistry and cancer research to advance scientific knowledge and medical applications.

Research topics

• Computer Science
• Economics
• Chemistry
• Microeconomics
• International trade
• Composite material
• Business
• Cell biology
• Biology
• Internal medicine
• Biochemistry
• Medicine
• Geography
• Economic geography
• Market economy
• Ecology
• International economics
• Materials science

Selected publications

• How do regional trade agreements change the risk exposure of the industrial chain?

  Economic Analysis and Policy · 2026-01-30

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  PublisherDOI

• Multiomics Analysis: Maternal Valine Intake during Protein Restriction Improves Fetal Intestinal Health in Pigs via IgA Homing

  Journal of Agricultural and Food Chemistry · 2026-02-12

  articleSenior authorCorresponding

  Protein restriction, while beneficial for maternal healthspan, poses risks to offspring development during lactation. This study investigated whether valine (Val) supplementation in maternal low-protein diets (LPDs) alleviates offspring developmental deficits via a gut-mammary axis. Maternal LPD impaired offspring growth, jejunal morphology, and barrier integrity while reducing levels of secretory immunoglobulin A (sIgA) and related immune mediators in both piglet jejunum and sow mammary gland. LPD suppressed CCL28-mediated sIgA homing to the mammary gland, which was restored by optimal Val supplementation (Val/Lys ratio: 0.88%). Val elevated serum valine metabolites and corrected LPD-induced depletion of beneficial genera in milk and the offspring gut, promoting microbial colonization. Thus, Val regulates sIgA immunity and microbial composition via the lactational axis to enhance the intestinal health of offspring under maternal protein restriction.

  PublisherDOI

• Do Digital Trade Rules Within the <scp>RTAs</scp> Promote Trade and Welfare Growth?

  World Economy · 2026-02-15

  article1st author

  ABSTRACT This study employs the OECD Digital Services Trade Restrictiveness Index framework to quantify changes in digital trade costs triggered by digital trade provisions within RTAs and incorporates these changes into a trade structure model that differentiates between intermediate and final goods. It assesses the trade and welfare impacts resulting from the implementation of digital trade rules under the Comprehensive and Progressive Agreement for Trans‐Pacific Partnership (CPTPP) and the Digital Economy Partnership Agreement (DEPA). Unlike traditional tariff concessions, digital trade rules—once implemented by a country—apply universally, thus significantly promoting trade for both member and non‐member countries. Further decomposition reveals that the changes in trade flows are primarily driven by intermediate goods. Welfare levels have substantially improved for CPTPP and DEPA members, mainly due to the welfare gains associated with reduced digital trade costs. Non‐member countries have also seen slight welfare improvements due to the spillover effects of these digital trade rules. Should China accede to either CPTPP or DEPA, it would generate positive trade and welfare effects for member countries, with China being the primary beneficiary. Non‐member countries would also benefit, albeit to a lesser extent than members, ultimately leading to an improvement in global welfare.

  PublisherDOI

• Increased maternal valine intake in low-protein diets accelerates growth performance of suckling piglets by improving mammary gland–fetal intestinal metabolism

  Animal nutrition · 2025-10-01 · 2 citations

  articleOpen accessSenior authorCorresponding

  Low-protein (LP) diets are increasingly recognized as a cost-effective and efficient strategy in the global livestock industry. Although previous studies have demonstrated that increased valine intake during pregnancy can improve reproductive performance and mammary gland development in gilts, the effect of the standardized ileal digestible valine-to-lysine ratio (Val/Lys) in LP diets during lactation is not well understood. A total of 60 lactating sows (Landrace × Large White; 4th parity) were randomized by backfat and weighed into 6 groups ( n = 10): a standard protein group (17% crude protein, Val/Lys of 0.87) and 5 LP diet groups (14.3% crude protein, Val/Lys of 0.64, 0.74, 0.84, 0.94 or 1.04). The experiment lasted from day 0 of lactation to day 21 of lactation. The results indicated that LP diets reduced ( P < 0.05) weaning weight and average daily gain (ADG) in piglets, as well as sow milk yield; whereas, increasing Val/Lys in LP diets improved ( P < 0.05) these parameters. A linear model determined an optimal Val/Lys ratio of 0.94 in LP diets for maximizing piglet ADG. Low-protein diets decreased jejunal trypsin levels in piglets, which increased ( P < 0.05) when Val/Lys was increased. Furthermore, LP diets reduced the expression of transporters (solute carrier family 38 member 2, SLC38A2) and metabolic enzymes (branched-chain amino acid transaminase 1 and 2, BCAT1 and BCAT2) in the piglet jejunum; conversely, increasing Val/Lys enhanced these expressions. Levels of L-valine, DL-arginine and L-threonine were found to decrease ( P < 0.05) in response to LP diets, as revealed by the results from sow serum metabolites. However, these concentrations rebounded ( P < 0.05) when Val/Lys was increased to 0.94. Correlation analysis revealed a positive association between sow serum valine metabolites and jejunal expression of SLC38A2, BCAT1 and BCAT2 in piglets. Low-protein diets also led to a decrease in the protein levels of metabolic enzymes ( P < 0.05), which were improved ( P < 0.05) by increasing Val/Lys. Finally, correlation analysis revealed a positive correlation between sow serum metabolites, jejunal enzyme expression and piglet growth performance. Collectively, growth performance in piglets may be impaired by LP diets for sows due to valine transport and catabolism being disrupted, whereas growth performance may be enhanced by increasing Val/Lys in LP diets via sow milk metabolites, thereby improving piglet digestion and absorption.

  PublisherDOI

• Immediate postpartum etonogestrel implant placement and breastfeeding: can we safely abandon the 24-hour rule?

  American Journal of Obstetrics and Gynecology · 2025-12-06 · 1 citations

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• Dietary bile acid supplementation improves the intestinal health and growth performance of piglets partially through the FXR/AQPs pathway

  Porcine Health Management · 2025-05-21 · 1 citations

  articleOpen access

  BACKGROUND: Maintaining the integrity of the structure and function of piglet intestines is crucial for their growth and health. This study aims to evaluate the effects of an antibiotic free diet supplemented with bile acid on gut health and growth performance of weaned piglets, and to explore their regulatory mechanisms. METHODS: Thirty-two weaned piglets were randomly divided into two groups and fed either a basal diet or a basal diet supplemented with 350 mg/kg bile acid. RESULTS: Dietary supplementation with bile acid increased the average daily gain (ADG) and final weight of piglets, and reduced the diarrhea incidence (P < 0.05), which was verified to be related to the improvement of lipid absorption, amino acid transport, and intestinal barrier function. Bile acid increased the concentration of lipase and decreased the concentration of total cholesterol, total glyceride, low-density lipoprotein, and urea nitrogen in serum (P < 0.05). Meanwhile, bile acid improved the mRNA expression of amino acid transporters in the intestine. On the other hand, bile acid decreased the pH values of the stomach, jejunum, and colon, and improved intestinal morphology (P < 0.05). The real-time quantitative PCR results showed that bile acid increased the mRNA expression of Occludin and ZO-1 in the duodenum and ileum (P < 0.05). Moreover, dietary bile acid supplementation altered the composition of the ileal microbiota in piglets and increased the relative abundance of Ligilactobacillus. In vitro, bile acid improved the repair of IPEC-J2 cells after injury and was shown to be associated with the activation of farnesoid X receptors (FXR) and increased expression of tight junction proteins and aquaporins (AQPs) proteins. CONCLUSION: This study found that dietary bile acid supplementation promotes the intestinal health and nutrient absorption partially through the FXR/AQPs pathway, ultimately improving growth performance of piglets.

  PublisherOA PDFDOI

• Dietary steviol glycosides mixture supplementation modulates the gene expression of gut chemoreceptors and enhances the antioxidant capacity in weaned piglets

  Porcine Health Management · 2025-02-06 · 1 citations

  articleOpen access

  BACKGROUND: Stevia glycosides (SGs) have been widely used as an ideal sugar alternative in the food industry. However, the potential application of SGs mixture in the diets of weaned piglets remains unexplored. This study aimed to investigate the effect of dietary SGs mixture supplementation on growth performance, gene expression of gut chemoreceptors, and antioxidant capacity in weaned piglets. METHODS: A total of 216 weaned piglets (Duroc × Landrace × Yorkshire, 7.36 ± 0.04 kg body weight) were randomly assigned to 6 groups (6 pens/group with 6 piglets/pen), and were fed with the basal diet supplemented with 0, 100, 150, 200, 250, or 300 mg/kg SGs mixture for 42 days. The serum, liver, longissimus thoracis, and jejunal samples were collected on day 43. RESULTS: The results showed that inclusion the SGs mixture in the diet did not have a significant impact on growth performance from days 1 to 28 (P > 0.05). But increasing the concentration of SGs mixture tended to linearly decrease the average daily gain from days 1 to 42 (P = 0.052). However, 150 mg/kg SGs mixture supplementation significantly increased the mRNA expression of taste receptor family 1 member 2 (T1R2) and glucose transporters 2 (GLUT2) in the jejunum (P < 0.05), while 150 and 200 mg/kg SGs mixture supplementation significantly increased T1R3 mRNA expression (P < 0.05). Moreover, 150 mg/kg SGs mixture supplementation significantly reduced serum malondialdehyde content (P < 0.05). Increasing the concentration of SGs mixture linearly and quadratically increased serum total superoxide dismutase (T-SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activity, as well as hepatic T-SOD, GSH-Px activity, and muscle total antioxidant capacity contents (P < 0.05). Furthermore, piglets fed a diet supplemented with 100 mg/kg SGs mixture had higher serum T-SOD, CAT, and GSH-Px activities compared with the other treatments (P < 0.05). CONCLUSIONS: Therefore, our results suggest that dietary 100 ~ 150 mg/kg SGs mixture supplementation modulates gene expression of sweet taste recognition receptors and glucose transporters, while also enhancing the antioxidant capacity of weaned piglets.

  PublisherOA PDFDOI

• Nherf2 is a major determinant of bile acid pool dynamics and contributes to regulation of Western diet-induced obesity

  American Journal of Physiology-Cell Physiology · 2025-10-31

  articleOpen access

  Nherf2 −/− but not Nherf1 −/− mice demonstrate a resistance to diet-induced obesity. Notably, male Nherf2 −/− mice exhibit impaired glucose tolerance and insulin responsiveness, yet neither sex shows further worsening with diet challenge. In addition, elevated hepatic Cyp7a1 levels were observed in Nherf2 −/− mice, but there was reduced cholesterol absorption in the ileum, along with enlarged gallbladders and diminished ileal bile acid content, highlighting significant metabolic alterations linked to Nherf2 deficiency.

  PublisherDOI

• Effect of Dietary Neutral Detergent Fiber Intake on Improving Fecal Consistency in Gestating Gilts

  Animals · 2025-11-30

  articleOpen access

  Constipation is a common issue in sows, characterized by dry and hard feces or prolonged absence of defecation, which exerts adverse effects on the overall health and reproductive performance of sows. While dietary neutral detergent fiber (NDF), due to its physicochemical properties, can enhance satiety and promote gastrointestinal health. The present study aims to determine the effect of different dietary NDF intake levels on reducing constipation without impairing the reproductive capacity of gestating sows. A total of 110 primiparous crossbred gilts (Landrace × Yorkshire) were randomly assigned to five groups with different NDF levels of 19.28% (Group A), 21.36% (Group B), 22.08% (Group C), 22.67% (Group D), and 23.43% (Group E), respectively. The daily feed intake was adjusted across groups to ensure a gradual increase in NDF intake from Group A to Group E, while maintaining consistent intake of other nutrients. The results revealed that dietary higher NDF intake (Groups D and E) significantly reduced the rates of constipation and stereotypic behaviors in gilts (p &lt; 0.05). The experiment lasted for two parities, starting from day 30 of the first parity gestation to the end of parturition in the second parity. During the second parity, all groups were fed the same diet, and only the reproductive performance of the sows was observed and recorded. Notably, NDF intake had no significant effect on gilts’ first-parity reproductive performance. This study confirms that an appropriate increase in dietary NDF intake can alleviate constipation in gilts. This finding provides critical, targeted references for optimizing nutritional strategies in primiparous gilt management, filling the void in tailored dietary guidelines for this understudied group and offering a practical solution to balance production efficiency and animal stress in commercial pig farming.

  PublisherDOI

• How the digital trade rules in the comprehensive and progressive agreement for trans-pacific partnership affect the restructuring of global value chains?

  Applied Economics · 2025-11-05

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Frequent coauthors

• Liaobin Chen

  Zhongnan Hospital of Wuhan University

  143 shared

• Hui Wang

  Capital Medical University

  94 shared

• Yulong Yin

  Hunan Agricultural University

  83 shared

• Bie Tan

  Hunan Agricultural University

  71 shared

• Wenkai Ren

  South China Agricultural University

  63 shared

• Jie Yin

  Hunan Agricultural University

  62 shared

• Yinxian Wen

  61 shared

• Yangfan Shangguan

  Zhongnan Hospital of Wuhan University

  59 shared

Labs

• Xiao Lab @ StanfordPI

Awards & honors

• 2025 V Scholar Award
• 2025 Baxter Faculty Scholar