We want to understand the dynamics of microbiome transmission within households, particularly before and after disturbances like routine antibiotic treatment.

Previous work has indicated that cohabiting individuals share many microbial strains, but we don't know how frequently microbes are transmitted between individuals and surfaces in a household, and how this transfer is affected by disturbances like antibiotic treatment.

We are looking for pairs of healthy, cohabiting adults to participate in our study of household transmission of the microbiota. Both romantic and platonic housemates are eligible to participate, as are undergraduate students who live in the same dorm room, suite, or house

Participants will not be enrolled if any of the following conditions are met: pregnant or planning to become pregnant; current medications other than birth control or hormone therapy (if planning to take ciprofloxacin); chronic health conditions; recent illness, immunizations, international travel (past month); recent hospitalizations or antibiotic use (past 3 months); adverse reactions to fluoroquinolone antibiotics.

Check your eligibility for this study here.  For participant's rights questions, contact 1-866-680-2906.

We will ask you to collect stool and saliva samples every week for two months, and daily for up to three weeks. We will also ask you to collect occasional swabs of your pets and household surfaces. We may also ask one person in each cohabiting pair to take a five-day course of the antibiotic ciprofloxacin to understand how disturbances to the microbiome affect transmission dynamics.

We will use genome sequencing techniques to understand what microbes are present, how they change over time, and how they move between people and surfaces in a household. New bioinformatic techniques are making it easier to track specific bacterial strains, and we will use these techniques to understand how microbes move between people and surfaces in a household.

The main reason to participate is to help scientists learn more about the microbiome! Eventually, studies like this one may help scientists understand how to change the microbiome to keep people healthy—but in the meantime, it’s fascinating to learn more about the microbes that surround us.

Another reason to participate is to learn about your own microbiota. You will have the option of meeting with the study staff once the study is complete (which may take several years) to find out what we’ve learned about the microbes in your household. Please note that we don’t yet know enough about the microbiota to provide specific health and medical advice based on what we learn.

We are also offering compensation to participants: $150 for participants who do not undergo antibiotic treatment, and $250 for participants who do undergo antibiotic treatment. We hope that this compensation will offset the inconvenience of sampling, but this study will be most rewarding if you understand why we’re doing this research and want to help.

We will give you flushable stool sample collection sheets, which have adhesives that allow them to stick to your toilet. You will use the provided sterile swabs and tubes to collect stool samples, and you can flush the remaining materials.

Click here to watch a one-minute video that shows the sampling materials and procedures.

You will need to store the samples in your home freezer for most of the study. We will give you boxes, Ziploc bags, an insulated bag, and a cooler pack to make sure the samples are isolated from the rest of your freezer and stay frozen. We will provide all sampling and sample storage materials, and we will pick up the samples at the end of the study or sooner, as space dictates.

That's ok!  Although we will ask you to collect daily microbiota samples for up to three weeks, we understand that the unpredictability of daily schedules, weekend trips, and other factors may sometimes make it hard to collect the samples we request. We would be grateful for your participation even if you miss a day or two of sampling here or there. If you have extended trips planned (longer than a few days), please let the study coordinators know so we can decide together whether your schedule can accommodate this study.

Most participants in similar, previous studies have done their microbiome sampling at home, but some participants find it easier or more convenient to keep a second sampling kit at the office. We are happy to provide a second sampling kit in this case. Please note that you will need access to a freezer in your office for several weeks if you choose to store samples there.

No. The goal of this study is to understand how microbes move between people and places in everyday life rather than in cases of deliberate microbial transfer.