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Liver Enzyme Nearly 70% Higher in Children With Obesity

A biomarker study links childhood obesity to higher liver stress enzymes and widespread changes in gut bacteria and blood chemistry.

By Dr. Josh Axe · November 8, 2026 · 1 source · Watch

Photo: Pexels

At a glance

What they found: Kynurenine and 3-nitrotyrosine, tied to inflammation and oxidative stress, rose.
Who was studied: 57 Mexican children grouped by weight: 15 normal weight, 8 overweight, 34 with obesity.

Children with obesity showed a liver stress marker nearly 70% higher than normal-weight peers, plus widespread gut bacteria and blood chemistry shifts, according to an Integrated multi-omics analysis reveals distinct metabolic signatures and gut microbiome alterations across the pediatric obesity spectrum published November 1, 2026 in Gut Microbes.

1,088fecal changes

95shifted gut bacteria

57children studied

Researchers studied 57 Mexican children by BMI: 15 normal weight, 8 overweight, 34 with obesity. The team ran liver enzyme panels, untargeted stool and blood chemical profiling, gut bacteria gene sequencing, and antibiotic-resistance testing, with demographics comparable across groups. Gamma-glutamyl transferase, or GGT, a liver stress marker, measured 25.5 U/L in children with obesity versus 15.0 U/L in normal-weight children, a gap of nearly 70%. Profiling found 1,088 altered stool compounds and 1,041 altered blood compounds comparing children with obesity to normal-weight children, touching amino acid processing, energy metabolism and nucleotide pathways. Kynurenine and 3-nitrotyrosine, tied to inflammation and oxidative stress, rose; bile acids and purine-related compounds fell. Sequencing found 78, 95 and 28 differing gut bacteria types across overweight-vs-normal, obese-vs-overweight, and obese-vs-normal comparisons, with the bacterial mix growing more scattered in obesity.

Specific gut bacteria tracked closely with specific gut chemicals, including one bacterial family linked to a short-chain fatty acid gut microbes make from fiber, and another genus linked to a bile acid byproduct. The authors said these pairings map to pathways connecting short-chain fatty acids, bile acids and amino acid byproducts to obesity biology. Short-chain fatty acids generally help maintain the gut lining and regulate inflammation; this study did not test whether restoring them changes outcomes in children.

Liver Stress Enzyme Nearly 70% Higher in Children With Obesity

Gut Microbes, 2026, Arredondo-Hernandez et al.

This cross-sectional snapshot compares groups at one timepoint, showing a link, not proof that obesity causes these biomarker or bacterial patterns. Each group was small, especially the 8 overweight children, so larger studies with more children in each group are a logical next step.

Dr. Axe’s Take

A liver enzyme nearly 70% higher in kids with obesity, paired with gut bacteria that lose their short-chain-fatty-acid producers, tells me the gut and liver are under stress together in childhood obesity, not separately. I'd watch fiber intake closely in kids carrying extra weight: vegetables, beans, berries and whole grains feed the bacteria that make protective fatty acids, while cutting refined carbs and added sugar eases pressure on the liver. I'd also ask a pediatrician about tracking liver enzymes as part of routine bloodwork for kids above a healthy weight. Pair that with daily movement and regular meal timing.

— Dr. Axe

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Study summary

Who: 57 Mexican children: 15 normal weight, 8 overweight, 34 with obesity; demographics comparable across groups
Design: Observational, cross-sectional biomarker study with liver enzyme testing, stool and blood chemical profiling, gut bacteria gene sequencing and antibiotic-resistance testing
Dose: Not applicable; no intervention given, biomarkers measured at one timepoint
Primary result: Liver stress enzyme GGT: 25.5 U/L in children with obesity vs 15.0 U/L in normal-weight children, about 70% higher
Secondary: 1,088 altered stool compounds and 1,041 altered blood compounds (obese vs normal weight); 78, 95 and 28 gut bacteria types differed across the three group comparisons
Funding / conflicts: Funder listed in the journal record: Fundación Gonzalo Río Arronte. Conflicts not reported in the abstract.
Date: Nov 1, 2026