Open Menu Close Menu Open Search Close Search

The purpose of this study is to determine whether taking two different forms of a probiotic, known as Bifidobacterium animalis subsp. Lactis (or B. Lactis for short) changes the bacteria balance in your intestines, as compared to a placebo. These potential changes may have effects on gut health, obesity risk and chronic inflammation; in addition, these changes may have an effect on general well-being such as sleep and physical activity patterns. Probiotics are known as “good” bacteria because they help keep your gut healthy by helping with your digestion. Probiotics can be found in supplements and some foods like yogurt, sauerkraut, pickles and miso soup.

Target Population
Individuals, ages 18 years and older

Major Exclusions
• Vegetarians or vegans
• Currently pregnant, planning to become pregnant or breastfeeding
• Having irregular bowel movements (<1 time per day)
• Diabetes or taking diabetes medications (except for metformin for pre-diabetes)
• Diagnosis of kidney, liver, heart, gallbladder or gastrointestinal diseases
• If you consume 2 or more Alcoholic drinks per day
• If you smoke tobacco or marijuana, or used marijuana products (incl. CBD oil or edibles) in the last 6 months
• If you regularly use any probiotic or prebiotic supplements; however, subjects who are willing to refrain from the use of probiotics supplements for 30 days prior to their enrollment and throughout the entire study may be considered eligible.

Length of Study
5 months

Number of Visits
2 screening visits, one enrollment visit; three cycles of three visits each with a 28 days reset period in-between cycles. Each study visit (except for the enrollment visit) will involve the collection of blood, urine, and stool samples, as well as medical information (i.e. waist circumference, weight, vitals, etc.), filling out questionnaires, and completing dietary recalls


Can I work?
Yes, but if subjects employed by Tufts University qualify to participate in the study, they cannot participate as subjects during hours in which they are being compensated by Tufts University for their regular work. This includes the use of vacation, personal days and sick time.

Study Diet
Subjects must maintain their regular diet throughout the trial and avoid taking probiotics supplements (other than those given to you by the study team) for the duration of the study. Subjects will be required to take a probiotic supplement or placebo, up to 3 capsules a day (3 capsules per day for approximately the first 3 days of each cycle, then only one capsule per day for the remaining 25 days in each cycle).

$45 for screening visits ($20 for 1st screening visit, $25 for 2nd screening visit), and up to $1250 for participants who qualify and complete the entire study