Author Archives: Francisco Fernandez, MD

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are synthetic compounds used in a wide variety of industrial and consumer products because of their resistance to heat and unique surfactant properties. Uses include nonstick products, such as Teflon, stain- and water-resistant materials, paints, and firefighting foams.  Perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), and perfluorooctanoic acid (PFOA) are commonly […]

Variation in gut microbiome composition underlies numerous human phenotypes and health outcomes, such as immune function, metabolic disorder, cancer, and psychiatric traits. These variations have been attributed largely to environmental factors, including diet, antibiotic exposure, and birth modality.  Some studies have identified genetic associations with the overall composition of the gut microbiota, in addition to […]

Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gut mucosa that is thought to increase the risk of colon cancer. The disease typically starts before middle age with symptoms such as abdominal pain and weight loss.  The cause is unknown, but genetical, environmental, and immunological factors are all believed to play a […]

Small cell lung cancer is the least common type of lung cancer, but it spreads faster than non-small cell lung cancer. Early lung cancer screenings can detect small cell lung cancer before it spreads when the disease is most treatable by methods like radiation therapy, immunotherapy, and chemotherapy. An estimated 15% of people diagnosed with […]

Migraine is a highly prevalent brain disorder characterized by disabling attacks of moderate-to-severe pulsating and usually one-sided headaches that may be aggravated by physical activity and can be associated with symptoms such as hypersensitivity to light and sound, nausea, and vomiting. It has a lifetime prevalence of 15-20% and is ranked as the second most […]

Vitamin K is a fat-soluble vitamin that comes in two forms. The main type is called phylloquinone, found in green leafy vegetables like collard greens, kale, and spinach. The other type, menaquinones, are found in some animal foods and fermented foods, and can also be produced by bacteria in the gut microbiome.  In a recently […]