Evaluation of Potential Probiotics Isolated from Human Milk and Colostrum

Abstract

Several studies have demonstrated a diversity of bacterial species in human milk, even in aseptically collected samples. The present study evaluated potential probiotic bacteria isolated from human milk and associated maternal variables. Milk samples were collected from 47 healthy women and cultured on selective and universal agar media under aerobic and anaerobic conditions. Bacterial isolates were counted and identified by Biotyper Matrix-Assisted Laser Desorption Ionization-Time of Flight mass spectrometry and then tested for probiotic properties. Total bacteria in human milk ranged from 1.5 to 4.0 log CFU/mL. The higher bacterial counts were found in colostrum (mean = 3.9 log CFU/mL, 95% CI 3.14-4.22, p = 0.00001). The most abundant species was Staphylococcus epidermidis (n = 76). The potential probiotic candidates were Lactobacillus gasseri (n = 4), Bifidobacterium breve (n = 1), and Streptococcus salivarius (n = 4). Despite the small sample size, L. gasseri was isolated only in breast milk from mothers classified into a normal weight range and after a vaginally delivered partum. No potential probiotics showed antagonism against pathogens, but all of them agglutinated different pathogens. Nine bacterial isolates belonging to the species L. gasseri, B. breve, and S. salivarius were selected as potential probiotics. The present study confirms the presence in breast milk of a bacterial microbiota that could be the source of potential probiotic candidates to be used in the formula of simulated maternal milk.

Breast Milk, a Source of Beneficial Microbes and Associated Benefits for Infant Health

“…This translocation of bacteria from maternal gut to mammary gland involves complex interactions between epithelial cells, immune cells, and bacteria [12,221]. Evidence supporting the entero-mammary pathway includes the presence of bacterial communities in colostrum collected before first infant suckling [222].…”

“…A number of studies have isolated potentially probiotic bacteria from human breast milk [191,222,[264][265][266][267][268]. Traditionally, species of Lactobacillus and Bifidobacterium are most commonly used as probiotics in humans and have a long history of safe use.…”

Staphylococcus epidermidis in feedings and feces of preterm neonates

“…This species seems to play a beneficial role in infants by inhibiting virulent pathogens and educating the innate immune system [3]. Several studies have shown that S. epidermidis is the predominant bacteria in colostrum and milk from healthy women [4][5][6][7][8][9][10] and there is a mother-to-infant transmission through breastfeeding [11]; in fact, its presence is known to be a differential trait of the fecal microbiota of breast-fed infants when compared to that of formula-fed ones [10,[12][13][14][15][16], being already present in the first meconium obtained from both term and preterm breastfed neonates [17,18]; however, coagulase-negative staphylococci (CNS) have received a marginal attention regarding their role in the early colonization of the infant gut in contrast to lactobacilli, bifidobacteria and other gut-associated strict anaerobes.…”

Advances in the analysis of “less‐conventional” human body fluids: An overview of the CE‐ and HPLC‐MS applications in the years 2015–2017

“…The continuous growth in the number of reports dedicated to BM analysis confirms the potential of this fluid to provide reliable information on human exposure to different compounds. Thanks to the presence in human milk of probiotics and prebiotics, breastfeeding is nutritional and immunologically/microbiologically essential for newborn health . In cases in which breastfeeding is not possible, a new formula of substitutive products, that simulates human milk in the best feasible way, must obviously be developed.…”