Scientists discovered that a common food additive called polysorbate-80 can cause inflammation in the intestines. In this study, researchers found that a beneficial bacteria called Lactobacillus acidophilus (LA) may help protect the gut from this damage. When they gave LA to animals with inflamed intestines from the food additive, the bacteria helped reduce inflammation, restore healthy gut bacteria balance, and improve overall health. This suggests that probiotics might be a natural way to counteract some harmful effects of common food additives we eat every day.

The Quick Take

  • What they studied: Whether a probiotic bacteria called Lactobacillus acidophilus could help fix intestinal inflammation caused by polysorbate-80, a common food additive found in many processed foods.
  • Who participated: The study was conducted in animal models (not humans) that were exposed to polysorbate-80 for 30 days to create intestinal inflammation, then treated with the beneficial bacteria for 14 days.
  • Key finding: Lactobacillus acidophilus treatment significantly reduced intestinal inflammation, improved gut bacteria balance, and decreased harmful inflammatory markers compared to untreated animals. The bacteria worked through a specific mechanism involving reducing a harmful compound called quinolinic acid.
  • What it means for you: This research suggests that probiotic supplements containing Lactobacillus acidophilus may help protect your gut from damage caused by food additives. However, this is early-stage research in animals, so more human studies are needed before making dietary changes. Talk to your doctor before starting any new supplements.

The Research Details

Researchers conducted an animal study to test whether a probiotic bacteria could reverse intestinal inflammation caused by a food additive. They first exposed animals to polysorbate-80 (a common ingredient in processed foods) for 30 days to create intestinal inflammation. Then they treated half the animals with Lactobacillus acidophilus bacteria for 14 days, while using a standard anti-inflammatory medication (mesalazine) as a comparison treatment.

The scientists examined the animals’ intestines under a microscope to see the damage, measured inflammatory chemicals in the gut, analyzed the composition of gut bacteria using genetic sequencing, and studied metabolites (chemical byproducts) in the intestines. This multi-layered approach allowed them to understand not just whether the bacteria helped, but how it worked at a biological level.

The study design allowed researchers to identify the specific mechanism: the bacteria reduced a harmful compound called quinolinic acid by lowering an enzyme called IDO-1 that produces it.

This research approach is important because it goes beyond simply checking if a treatment works—it reveals the biological pathway explaining why it works. Understanding the mechanism helps scientists develop better treatments and predict which other conditions might benefit from similar approaches. The combination of microscopy, protein analysis, bacterial DNA sequencing, and chemical analysis provides strong evidence for the findings.

Strengths: The study used multiple complementary testing methods (histology, protein analysis, genetic sequencing, and metabolite analysis) to confirm findings from different angles. The researchers included a positive control group using an established medication for comparison. Limitations: This research was conducted in animals, not humans, so results may not directly apply to people. The study doesn’t specify the exact number of animals used. No human clinical trials have yet confirmed these findings in real patients.

What the Results Show

Lactobacillus acidophilus treatment significantly reduced intestinal damage and inflammation in animals exposed to polysorbate-80. Animals treated with the bacteria showed improved body weight (they stopped losing weight), reduced disease activity scores, and healthier intestinal tissue under the microscope compared to untreated animals.

The bacteria reduced inflammatory chemicals in the gut, specifically decreasing TNF-α and IL-6 (proteins that cause inflammation) while increasing protective proteins called ZO-1 and Claudin-1 that strengthen the intestinal barrier. This means the bacteria helped both reduce inflammation and repair the protective lining of the gut.

The treatment also restored healthy gut bacteria balance by increasing bacterial diversity and promoting beneficial bacteria, particularly increasing Lactobacillus species and improving the ratio of Firmicutes to Bacteroidetes bacteria—both markers of a healthier microbiome.

Most importantly, the bacteria worked by reducing quinolinic acid, a harmful compound that promotes intestinal inflammation. It did this by decreasing IDO-1, the enzyme responsible for producing quinolinic acid. This explains the biological mechanism behind the beneficial effects.

The study found that Lactobacillus acidophilus improved overall microbial diversity in the gut, which is generally associated with better health. The bacteria also modified other intestinal metabolites (chemical compounds), suggesting it influences multiple aspects of gut chemistry beyond just quinolinic acid. These metabolic changes may contribute to the overall anti-inflammatory effects observed.

Previous research has shown that polysorbate-80 and similar food additives can damage the intestinal barrier and trigger inflammation in animal models. This study builds on that knowledge by demonstrating that probiotics may offer protection. The findings align with existing research showing that Lactobacillus species can reduce intestinal inflammation through various mechanisms. However, most prior studies focused on different causes of colitis, so this is one of the first to specifically examine polysorbate-80 damage.

This study was conducted in animals, not humans, so the results may not directly translate to people. The exact number of animals used wasn’t specified in the abstract. The study didn’t test different doses of the bacteria to find the optimal amount. It’s unclear how long the protective effects would last after treatment stops. The research doesn’t address whether the bacteria would work in people already taking other medications. No information is provided about potential side effects or safety concerns in humans.

The Bottom Line

Based on this research, there is preliminary evidence (low to moderate confidence) that Lactobacillus acidophilus may help protect against intestinal inflammation from food additives. However, recommendations cannot be made for human use yet since this is animal research. If you’re concerned about food additives and gut health, focus on eating less processed food and more whole foods. If interested in probiotics, consult your doctor before starting supplements, especially if you have existing digestive conditions or take medications.

This research is most relevant to: people with inflammatory bowel conditions, those concerned about food additives in their diet, and researchers studying probiotic treatments. It’s less immediately relevant to people without digestive issues, though the findings may eventually inform general dietary recommendations. People with compromised immune systems should consult doctors before taking probiotic supplements.

In the animal study, benefits appeared within 14 days of treatment. If human studies eventually confirm these findings, realistic timelines would likely be weeks to months to see improvements in digestive symptoms. Long-term effects and whether benefits persist after stopping treatment remain unknown.

Want to Apply This Research?

  • Track daily digestive symptoms (bloating, discomfort, bowel regularity) on a 1-10 scale, along with processed food intake and any probiotic supplements taken. This creates a personal data log to identify patterns between food additives, probiotics, and digestive health.
  • Users could set a goal to reduce processed food consumption by 10-20% weekly while tracking which foods contain polysorbate-80 (common in salad dressings, ice cream, and baked goods). Simultaneously, they could experiment with adding more whole foods and, with doctor approval, try a probiotic supplement containing Lactobacillus acidophilus while monitoring digestive changes.
  • Create a weekly digestive health score combining symptom severity, energy levels, and food quality. Compare weeks with high processed food intake to weeks with lower intake and probiotic use. Track changes over 8-12 weeks to identify personal patterns, then adjust diet and supplementation based on individual results.

This research was conducted in animals and has not been tested in humans. The findings do not yet support clinical recommendations for human use. Polysorbate-80 is currently considered safe by food regulatory agencies at typical consumption levels. Before starting any probiotic supplement, consult with your healthcare provider, especially if you have inflammatory bowel disease, a compromised immune system, or take medications. This article is for educational purposes and should not replace professional medical advice. Always discuss dietary changes and supplements with your doctor.