Dr. Rajesh, Bacterial gastroenteritis happens when bacteria causes an infection in our gut. It causes inflammation in our stomach and intestines. We may also experience symptoms like vomiting, severe abdominal cramps, and diarrhea. The best natural remedies without using any antibiotics are:

1. Honey specially Manuka honey

2. Cabbage has shown the ability to combat bacteria

3. Onions and Garlic

4. Ginger

5. Colloidal silver

6. Oil of oregano

7. Echinacea

I recommend Tarafdar's answer

Best Regards