Foods that may be beneficial for optimal immune system and gut microbiome health in animals.

The immune system is the protective mechanism animals rely on in the face of external threats experienced every day in their immediate environments. While the animal is outside on walks, interacting with other animals, and or even interacting with humans at home, the immune system works hard around the clock to keep healthy, functioning immune cells circulating constantly in the body, primed and ready in the event of a pathogenic invasion. Providing the immune system with the energy it needs is vital for maintaining this 24/7 protection; nutrition powers the immune response just as it does for all other systems of the body.


The immune system is characterized by two different stages:

  1. The innate immune response is a fast-acting, nonspecific response that focuses on targeting the location of the infection with pro-inflammatory immune cells that identify and destroy pathogens.
  2. When the innate immune response isn’t enough to clear an infection, the adaptive immune response comes into play. This system is pathogen-specific, made up of T cells, B cells, and antibodies; it is through the adaptive immune response that the immune system is able to remember pathogens.


The gastrointestinal (GI) tract is considered the largest organ of the immune system, both facilitating digestion and housing the gut microbiome. The healthy microbes that live in the gut microbiome pay their rent by supporting the health of their host: boosting nutrient absorption, fighting pathogenic microbes in the gut, and strengthening the immune response. Thus, by taking care of the gut microbiota, the host can optimize its own immune capabilities.


Paying close attention to an animal’s diet is important for the regular nutritional support that the microbiome and immune system need. A few foods in general may be particularly beneficial for optimal immune health:

Buckwheat is a source of rutin, a phytonutrient with antioxidant power, and a source of prebiotic fiber. Buckwheat is a pseudograin, which means it is naturally gluten-free. It has been shown to increase circulating levels of important detoxification molecules supporting liver function.1

Spanish black radish is a cruciferous vegetable — the same family that includes kale and Brussels sprouts. Spanish black radish is rich with glucosinolates, phytonutrients that are associated with liver, gallbladder, and general digestive support.2 This vegetable also promotes liver detoxification through efficient elimination and by stimulating bile function.3,4

Beetroot is rich with nitrates, which convert to nitric oxide in the body for promoting vascular function and immunity. Phenolics from beets support antioxidation, and betalains are linked with healthy inflammation.5 Another phytonutrient, betaine, promotes detoxification and immune function in the face of stress.6

Brussels sprouts, like Spanish black radish, contain glucosinolates as well as phenolic compounds and carotenoids.7 These phytonutrients are known for regulating the immune system. Additionally, the sulfur in Brussels sprouts is linked to liver detoxification.8

Chlorophyll extract is visible as the green pigment found in plants, and is highly valuable for its antioxidant and anti-inflammatory activity. Research has linked chlorophyll to wound repair, red blood cell activity, healthy hemoglobin levels, and gut microbiome modulation.9-11

Proper immune system care relies on proper nutrition. The intricate relationship between the GI tract, the microbiome, and the immune response is important for whole-body health; and feeding this relationship with the right nutrients is the best way to maintain this health.

1Gimenez-Batida JA, Zielinski H. Buckwheat as a functional food and its effects on health. J Agric Food Chem. 2015;63:7896-7913.

2N’jai, A.U., Kemp, M.Q., Metzger, B.T., et. al. Spanish black radish (Raphanus sativus L. Var. niger) diet enhances clearance of DMBA and diminishes toxic effects on bone marrow progenitor cells. Nutr Cancer. 2012;64(7):1038-48.

3Evans, M., Paterson, E., & Barnes, D.M. An open label pilot study to evaluate the efficacy of Spanish black radish on the induction of phase I and phase II enzymes in healthy male subjects. BMC Complement Altern Med. 2014;14:475.

4Lugasi, A., Blázovics, A., Hagymási, K., Kocsis, I. and Kéry, Á.Antioxidant effect of squeezed juice from black radish (Raphanus sativus L. var niger) in alimentary hyperlipidaemia in rats. Res. 2005;19:587-591.

5Wink DA, Hines HB, Cheng RY, et al. Nitric oxide and redox mechanisms in the immune response. J Leukoc Biol. 2011;89(6):873-891.

6Craig SA. Betaine in human nutrition. Am J Clin Nutr.2004;80(3):539-49.

7Melrose J. The Glucosinolates: A Sulphur Glucoside Family of Mustard Anti-Tumour and Antimicrobial Phytochemicals of Potential Therapeutic Application. Biomedicines. 2019 Aug 19;7(3):62.

8Higdon, Jane. 2017. Isothiocyanates. Oregon State University Linus Pauling Institute Micronutrient Information Center.

9Solymosi K, Mysliwa-Kurdziel B. Chlorophylls and their Derivatives Used in Food Industry and Medicine. Mini Rev Med Chem. 2017;17(13):1194-1222.

10Li Y, Cui Y, Lu F, Wang X, Liao X, Hu X, Zhang Y. Beneficial effects of a chlorophyll-rich spinach extract supplementation on prevention of obesity and modulation of gut microbiota in high-fat diet-fed mice. J Funct Foods. 2019;60:103436.

11Xavier-Santos D, Bedani R, Lima ED, Saad SM. Impact of probiotics and prebiotics targeting metabolic syndrome. J Funct Foods. 2020 Jan 1;64:103666.



Dr. Doug Knueven earned his veterinary degree from Ohio State University in 1987 and is the owner and medical director of Beaver Animal Clinic in Beaver, Pennsylvania. He has been practicing integrative veterinary medicine since 1995, and earned certification in veterinary acupuncture, veterinary Chinese herbal medicine and veterinary chiropractic. Dr. Knueven also has advanced training in natural nutrition, Chinese food therapy, massage therapy and homeopathy. He is a long-time member of the AHVMA, and lectures on holistic medicine at veterinary conferences. Dr. Knueven has written two books: Stand by Me: A Holistic Handbook for Animals, Their People and the Lives They Share Together, and The Holistic Health Guide: Natural Care for the Whole Dog.


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