Berry Kefir Smoothie with Spinach

Probiotics to Support Athletic Performance

Probiotics are live food supplements with beneficial effects on the health of the host.¹ Probiotics occur naturally in fermented foods such as yogurt, kefir, sauerkraut, kimchee and soybean-based miso and tempeh.² Over the past several years, the consumption of fermented foods has gained in popularity as a way to naturally improve intestinal tract health, enhance the immune system, reduce symptoms of lactose intolerance and allergic conditions, and reduce the risk of certain cancers.¹ʼ² The adult human intestinal tract contains approximately 400 different bacterial species. Although these species are usually stable, they can be influenced by a number of factors including age, immune status, antibiotic use, stress, alcohol use, and diet. The consumption of probiotic containing foods may help to promote reestablishment of “good” bacteria and help to balance the colonic intestinal flora.² The mechanism behind the potential beneficial effect of probiotics is still under investigation, but it has been suggested it may be related to their ability to modify gut pH, produce antimicrobial compounds, out compete “bad” bacteria for available nutrients and/or through the production of lactase (the enzyme required to digest lactose).¹ʼ³

Since different strains of bacteria exert different effects on human health it can be difficult to draw definite conclusions from research on probiotics. There is even less research investigating the role probiotics might play in athletic performance. At present, there is no scientific evidence to indicate that probiotics have a direct performance enhancing effect.² However, it has been suggested that consuming probiotics may provide athletes with secondary health benefits that could positively influence athletic performance. These potential benefits include improved recovery from fatigue, enhanced immune function and assist in the maintenance of healthy intestinal tract function.²

Summary of proposed benefits for athletes:

  • Probiotics may help to improve immune function in fatigued athletes and help to reduce the number of sick days experienced during training .
  • Probiotics may assist in the reduced severity of respiratory infection and gastrointestinal upset (if/when they occur).
  • No negative effects have been reported regarding probiotic ingestion among athletes.
  • No current evidence to suggest that probiotics can improve athletic performance.

* Probiotics are not recommended for severely, immune compromised individuals.



Berry Kefir Smoothie with Spinach

Makes 2 large servings


1 cup plain kefir

1/2 cup low fat milk

2 cups frozen berries

1 tsp honey

1 tbsp chia seeds

1/2 cup spinach


  1. Place all of the ingredients in a blender and blend at high speed until smooth. Serve at once. (If mixture is too thick to blend, add a bit more milk)

Recipe adapted from: