The Influence of Pet Ownership on Gut Microbiota Composition and Cardiovascular Disease Risk Among 50 to 85-Year Old United States Adults | HABRI

The Influence of Pet Ownership on Gut Microbiota Composition and Cardiovascular Disease Risk Among 50 to 85-Year Old United States Adults

Principal Investigator

Katharine Watson, BVMS (Indiana University)


Cardiovascular disease (CVD) is the leading cause of death and disability and the most common non-communicable disease in the developed world. In 2016, 31% of all global deaths and 25% of US deaths were caused by cardiovascular diseases. Over the past decade, the gut microbiota has been shown to play an important role in cardiovascular disease development. The modest protective effect of pet ownership on CVD appears to exist and this effect prompted the American Heart Association to publish a review paired with a position statement that “pet ownership, especially dogs, may be reasonable for reduction of CVD risk”. As pet ownership is associated with benefits to the gut microbiota of infants, it is probable that adults who live with pets may have similar benefits and that these may play a role in CVD risk reduction.


This study will examine the association of cat and dog ownership with the human gut microbiome, differences between the gut microbiome of those with and without CVD, and whether differences in the gut microbiome of cat and dog owners mediate prevalence risk of CVD.


It is hypothesized that:

  1. Gut microbiota richness (number of bacterial operational taxon units or OTUs) and species diversity differs between pet owners and non-pet owners,
  2. Gut microbiota differs between adults with and without CVD, and
  3. Differences in the gut microbiota of pet owners relative to non-owners are associated with reduced CVD risk.


Data on pet ownership, personal characteristics such as health and lifestyle, and gut microbiome genome sequences from 50-85-year old men and women will be obtained from the American Gut Project. Gut microbial species will be characterized and statistical analyses will be used to estimate the association between microbial species, cat and dog ownership, and CVD. A mediation analysis will test whether the gut microbiome influences any difference between the prevalence of CVD among cat and dog owners and non-owners.

Expected Results

Researchers expect:

  1. Dog ownership to be associated with reduced CVD risk,
  2. Dog and cat owners to have richer (more abundant) and diverse fecal microbiota,
  3. The microbial communities of participants without CVD to be richer and more diverse than those without CVD,
  4. The pre-dominant bacteria to differ between participants with and without CVD, and
  5. The fecal microbiota composition of pet owners to be negatively associated with CVD risk.