# Type of diet has no major influence on inflammatory response in a Saddleback pig model

## TL;DR

Adding pectin or inulin to an unhealthy diet in pigs did not reduce inflammation linked to obesity.

## Contribution

This study shows fermentable carbohydrates do not resolve obesity-related inflammation in a pig model.

## Key findings

- Faecal SCFA concentrations decreased and faecal pH increased over the feeding period.
- Inflammatory markers in abdominal fat were higher than in subcutaneous fat.
- Pectin or inulin supplementation did not reduce low-grade inflammation in obese pigs.

## Abstract

Fermentable carbohydrates and resulting short-chain fatty acids (SCFAs) received attention via modifying potential on obesity-associated systemic low-grade inflammation. However, their effects on inflammation remain poorly understood. In this study, the anti-inflammatory properties of pectin or inulin supplementation were investigated in an atherogenic-fed pig obesity model. Pigs were divided into three atherogenic-fed groups with or without 5% pectin/inulin supplementation (AD, ADp, ADi, n = 10) and a conventional-fed group (CD, n = 10) for a 15-week feeding period. We demonstrated that faecal SCFA concentrations decreased and faecal pH increased in all groups over the feeding period (P < 0.05). SCFA concentrations were comparable between colon and faeces in all groups. Liver inflammatory-marker expressions were on average < 1 in all groups, except TNF-α (AD < CD and ADi; P < 0.01). Inflammatory-marker expressions in abdominal adipose tissue exceeded subcutaneous marker expressions in all groups. AD showed significantly lower IL-1β and CD68 mRNA levels than CD (P < 0.03). Comparing the atherogenic diet groups, the IL-1β mRNA levels were higher in ADi versus AD and ADp (P = 0.02). Our data indicated that fermentable carbohydrates added to an atherogenic diet cannot resolve low-grade adipose tissue inflammatory associated with obesity.

The online version contains supplementary material available at 10.1038/s41598-025-92420-y.