MegaIgG2000 by Microbiome Labs

If loose stools or post-infectious gut upset keep hanging around, a serum bovine immunoglobulin (IgG supplement) is a practical trial. It’s useful when stool tests show low secretory IgA (your gut’s first-line antibody), elevated fecal calprotectin (an inflammation marker), or high zonulin (a permeability marker). People reacting to high-FODMAP foods, frequent travelers with traveler’s diarrhea history, athletes with gut symptoms during heavy training, and those with low-grade systemic inflammation on hs-CRP often report steadier stools within 2 to 4 weeks.

These bovine IgG antibodies stay in the intestinal lumen and bind microbial fragments such as lipopolysaccharide (LPS, a cell-wall toxin from certain bacteria), flagellin (a bacterial protein), and other antigens. By sequestering these irritants, they reduce the antigen load that keeps the immune system revved up in the gut. In practice, that can mean calmer signaling, less water pulled into the stool, and better barrier function, which is why some patients see improvements in fecal calprotectin and steadier stool form.

Take 4 capsules daily between meals or at bedtime with plenty of water. Between meals keeps the antibodies focused on binding antigens rather than food. You can open the capsules and mix the powder in a cool beverage. Expect changes in stool consistency within 2 to 4 weeks; give it 8 weeks for a fair trial. This is a maintenance-to-therapeutic dose; some clinicians double it short term for stubborn loose stools, then step back once stable.

Skip this if you have a beef allergy or alpha-gal syndrome, since it’s derived from bovine serum. It’s dairy-free (no lactose or casein), but those with severe milk-protein reactions should still use caution. Space it at least 48 hours away from oral vaccines (cholera, typhoid, rotavirus), which rely on antigens in the gut. If you’re on a strict low-protein plan for advanced kidney disease, discuss the extra 2 g protein per serving with your clinician.