Scientists conduct a study in which 100 adults with chronic diarrhea are divided into 2 groups of 50 people. one group is given a supply of yogurt that contains a certain kind of bacteria and the other group is given yogurt that is bacteria free. the study's participants and researchers do not know which group of subjects has the bacteria in the yogurt and which group does not. the scientists instruct the participants to eat the entire 8 ounces of yogurt once a day for a month and record the their bowel habits. this is an example of a(n) study.

Double blind study

Explanation:

A double-blind investigation is one in which neither the members nor the one performing the experiments realize who is getting a specific treatment.

This method is used to counteract inclination in research results.  

Double blind examinations are especially helpful for anticipating predisposition because of interest qualities or the placebo impact.

Double blind.

Explanation:

Double blind study may be defined as the experiment in which neither the experimenters nor the participants are aware about the particular treatment. This provide bias in the research.

The scientists do not know which yogurt contains the bacteria. They divide the people into two groups. Here, neither the researcher nor the participants know which yogurt contains bacteria. This is an example of the double blind research.

Thus, the answer is double blind.