In the interest of full disclosure — there is a risk of bacterial infection from probiotics and yogurt, even death. The odds appear to be very low (likely a lot lower than many prescription drugs). In some cases, a single case of an issue have been circulated into a alternative-medicine legend that one or another probiotic should be avoided.

• 80 reports for Lactobacillus bacteremia probiotic
• 10 for Bifidobacteria bacteremia probiotic
• 9 for Enterococcus bacteremia probiotic 
• 5 for Bacillus bacteremia probiotic
• For Saccharomyces see
  •  Saccharomyces cerevisiae Fungemia: An Emerging Infectious Disease
  • Infectious complications following probiotic ingestion: a potentially underestimated problem? A systematic review of reports and case series “The genus Saccharomyces was the most frequent with 47 (50.6%) cases, followed y Lactobacillus, Bifidobacterium, Bacillus, Pedioccocus and Escherichia with 26 (27.9%), 12 (12.8%), 5 (5.4%), 2 (2.2%) and 1 (1.1%) case, respectively. “

Some articles:

• The potential risks of probiotics among HIV-infected persons: Bacteraemia due to Lactobacillus acidophilus and review of the literature [2016].
• Incidence and outcomes of bloodstream infections among hematopoietic cell transplant recipients from species commonly reported to be in over-the-counter probiotic formulations[2016].
• Importance of Molecular Methods to Determine Whether a Probiotic is the Source of Lactobacillus Bacteremia [2016].
• “Lactobacillus Bacteremia(LB) was observed in 38 patients (0.34% of all positive blood cultures). Cancer (40%), immunosuppression (37%), and use of central venous devices (29%) were frequently associated with LB.” [2017]