No, not always. However, only in two circumstance that yogurt may be better than kefir. They are :
1. A commercially produced low fat flavored kefir will lose to a homemade yogurt. Especially if the kefir has been pasteurized after the fermentation process. Pasteuerisation after fermentation will kill whatever beneficial live strains there may be in kefir. Furthermore, low fat flavored means the addition of sweeteners which may be unhealthy as well.
2. If you know specifically what strains of bacteria you want, you may be able to find it in yogurt which may not be present in kefir.
That said, all things being equal, kefir DOES win hands down every time. Consider this:
• Yogurt contains only a few strains of bacteria, whereas kefir usually contains more than 50 strains of bacteria and yeasts combine. Kefir contains several major strains of friendly bacteria not commonly found in yogurt, Lactobacillus Caucasus, Leuconostoc, Acetobacter species, and Streptococcus species.
• Kefir also contains beneficial yeasts, such as Saccharomyces, which dominate, control and eliminate destructive pathogenic yeasts in the body. They do so by penetrating the mucosal lining where unhealthy yeast and bacteria reside, forming a virtual SWAT team that housecleans and strengthens the intestines. Hence, the body becomes more efficient in resisting such pathogens as E. coli and intestinal parasites.
• Yogurt is a probiotic while kefir is a pre as well as probiotic. This means to say kefir can actually, over a period of regular consumption, re-populate your gut.
• Kefir’s active yeast and bacteria provide more nutritive value than yogurt by helping digest the foods that you eat and by keeping the colon environment clean and healthy. Because the curd size of kefir is smaller than yogurt, it is also easier to digest, which makes it a particularly excellent, nutritious food for babies, the elderly and people experiencing chronic fatigue and digestive disorders. (source: kefir.net website).
• Kefir has a higher content of vitamin K2 while most yogurt, according to Dr Mercola, has almost no Vitamin K2. Vitamin K2 is essential for bone health as it plays an important role in calcium metabolism. It ensures calcium is deposited where it ought to be in our bones and teeth, not in our arteries or soft tissues (which causes pain due to calcium calcification)