Researchers found a type of helpful bacteria called Lacticaseibacillus casei in traditional Iranian dairy products that might help people with type 2 diabetes. When they tested this bacteria in rats with diabetes, it reduced liver damage and lowered blood sugar levels significantly over four weeks. The bacteria survived well in the stomach’s acidic environment and fought off harmful germs. While these results are promising, this is early-stage research in animals, so more human studies are needed before we know if it will work the same way in people.

The Quick Take

  • What they studied: Whether a specific probiotic bacteria found in yogurt and cheese could help protect the liver and lower blood sugar in animals with type 2 diabetes
  • Who participated: Laboratory rats that were given a chemical to create diabetes-like conditions, compared to control rats without diabetes
  • Key finding: The bacteria reduced liver damage markers by about 30-50% and cut blood sugar levels roughly in half over four weeks of treatment
  • What it means for you: This suggests probiotics might someday help diabetes patients, but this is animal research only. Don’t replace your diabetes medications with probiotics yet—talk to your doctor before trying any new supplements

The Research Details

Scientists started by collecting 15 different types of helpful bacteria from traditional dairy products made in Northwestern Iran. They tested each one to see which was toughest and most beneficial. The winning strain, called ad1, was then given to rats that had been made diabetic using a chemical called streptozotocin. The rats received this bacteria for four weeks while researchers measured changes in liver function tests, blood sugar levels, and liver tissue damage under a microscope.

This type of study is called a preclinical or animal study. Researchers use animals first to see if an idea is worth testing in humans. They can control everything about the rats’ environment and diet, which helps them understand exactly what the bacteria does.

The researchers measured several important markers: liver enzymes (ALT, AST, and ALP) that show liver damage, blood glucose levels, and actual tissue damage when they looked at the liver under a microscope.

Animal studies help scientists understand how treatments might work before testing them in people. This approach is important because it’s faster and safer than jumping straight to human trials. If the bacteria works in rats, it gives researchers confidence to design human studies. The fact that they tested the bacteria’s survival in stomach acid and bile is important because the bacteria has to survive these harsh conditions to reach the intestines where it can help.

Strengths: The bacteria was thoroughly tested for safety (it didn’t damage blood cells and responded to antibiotics). The researchers measured multiple markers of liver health and blood sugar, not just one. They looked at actual tissue damage under a microscope, which is more reliable than blood tests alone. Weaknesses: This is animal research, so results may not transfer to humans. The study doesn’t specify how many rats were used in each group. We don’t know if the benefits would last longer than four weeks. There’s no information about whether the bacteria would work as well in people with different genetics or lifestyles.

What the Results Show

The bacteria strain ad1 survived very well in conditions that mimic the human stomach and small intestine. At stomach acid levels (pH 2.5), about 71% of the bacteria survived after three hours. In bile (which helps digest fats), about 74% survived after four hours. This is important because many probiotics die before reaching your intestines.

When given to diabetic rats, the bacteria produced impressive results. Liver enzyme ALT dropped from 60.6 to 45.5 units (about 25% improvement). AST dropped from 93.5 to 60.1 units (about 36% improvement). ALP dropped from 264.1 to 191.3 units (about 28% improvement). These enzymes leak into the blood when the liver is damaged, so lower levels mean less damage.

Most dramatically, blood sugar dropped from 311.9 to 153.1 mg/dL—roughly cut in half. This is a significant change that would be very meaningful in diabetic patients. When researchers looked at liver tissue under a microscope, they saw less fat buildup and less overall damage in the rats that received the bacteria compared to untreated diabetic rats.

The bacteria also showed strong antibacterial activity, meaning it could fight off harmful germs. It was particularly effective against Staphylococcus aureus, a common infection-causing bacteria.

The bacteria showed strong ability to stick to surfaces (autoaggregation of 69.61%), which helps it colonize the gut and stay there longer. It was non-hemolytic, meaning it didn’t damage red blood cells—an important safety marker. The bacteria was sensitive to all eight antibiotics tested, which is good because it means it won’t spread antibiotic resistance. These safety characteristics suggest the bacteria is unlikely to cause harm, at least in animal models.

Other Lactobacillus strains have shown similar benefits for diabetes and liver health in previous animal studies, so this finding fits with existing research. However, this particular strain (ad1) appears to have stronger acid and bile tolerance than some previously studied strains, which could make it more effective. The liver protection effect is consistent with other probiotic research, but the magnitude of blood sugar reduction is notably impressive compared to many other single-strain studies.

This is animal research in rats, not humans—rats’ bodies work differently from ours in important ways. The study doesn’t specify the exact number of rats in each group or how they were divided. We don’t know if the benefits would continue beyond four weeks or if they’d work in people with different genetics, diets, or lifestyles. The study doesn’t compare this bacteria to other probiotics or to standard diabetes medications. We don’t know the right dose for humans or if it would work as well in people. There’s no information about potential side effects in humans.

The Bottom Line

This research is promising but very early-stage. Current confidence level: Low to Moderate for human application. Do not use this as a replacement for diabetes medications. If you have type 2 diabetes, continue taking prescribed medications and following your doctor’s advice. You might ask your doctor about probiotic supplements in general, but this specific strain isn’t available for human use yet. Eating fermented dairy products like yogurt with live cultures is generally safe and may have some benefits, but won’t replace medical treatment.

People with type 2 diabetes should be interested in this research as a potential future option. Researchers studying probiotics and metabolic health should pay attention. People with liver disease related to diabetes might find this relevant. However, this shouldn’t influence treatment decisions right now. People without diabetes don’t need to change anything based on this study.

In the rat study, benefits appeared within four weeks. If this ever becomes available for humans, it would likely take months to see meaningful changes in blood sugar or liver function. Don’t expect overnight results—metabolic changes take time. The research would need to progress through human trials (typically 2-5+ years) before this specific strain could be recommended for patients.

Want to Apply This Research?

  • If you have type 2 diabetes, track your fasting blood sugar readings weekly and note any probiotic supplements you take. Record liver function test results from your doctor’s visits (ALT, AST, ALP levels) every 3-6 months to monitor liver health trends over time.
  • Start eating more fermented dairy products with live cultures (yogurt, kefir, traditional cheeses) as part of a balanced diet. Log your daily probiotic food intake in the app. Pair this with consistent diabetes management: regular blood sugar monitoring, medication adherence, and healthy eating. Track how you feel—energy levels, digestion, and general wellness.
  • Create a long-term dashboard tracking: (1) Weekly fasting blood glucose readings, (2) Monthly notes on digestion and energy levels, (3) Quarterly liver enzyme results from doctor visits, (4) Daily probiotic food/supplement intake. Set reminders for regular doctor checkups to monitor liver health. Compare trends over 3-6 months to see if dietary probiotics correlate with any improvements in your diabetes markers.

This research was conducted in laboratory rats, not humans. The findings are promising but preliminary and should not be used to replace any prescribed diabetes medications or medical treatments. Probiotics are not regulated by the FDA the same way medications are. Before starting any probiotic supplement, especially if you have diabetes or liver disease, consult with your healthcare provider. This article is for educational purposes only and does not constitute medical advice. Individual results may vary, and what works in animals may not work the same way in people.