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Year : 2009  |  Volume : 50  |  Issue : 3  |  Page : 58-60 Table of Contents     

Determination of in-vitro antibacterial effects of breast milk

1 Department of Medical Microbiology/Parasitology, College of Health Sciences, Nnamdi Azikiwe University, Nnewi campus, Nigeria
2 Department of Pediatrics, College of Health Sciences, Nnamdi Azikiwe University, Nigeria
3 Department of Medical Microbiology/Parasitology, College of Medicine, University of Lagos, Nigeria

Date of Web Publication16-Nov-2010

Correspondence Address:
C N Akujobi
Department of Medical Microbiology/Parasitology, College of Health Sciences, Nnamdi Azildwe University, Nnewi campus
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Source of Support: None, Conflict of Interest: None

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Background:Breast milk undisputedly is the ideal baby food. It provides a lot of protective functions for the baby as well complete nutrition. It contains fat, proteins carbohydrates, vitamins and minerals. There have been various claims that it cures ailments. The study was therefore designed to substantiate those claims.
Objective: To determine the in vitro antibacterial effects of breast milk
Methodology:Expressed breast milk of nursing mothers who were not on antibiotics was challenged with 0.5 McFarland's standard of overnight cultures of common bacteria that cause infections. The mixture was sub cultured at 30 minutes, 1 hour and lastly 2 hour intervals. The plates were read the following day for evidence of growth.
Result:Overnight incubation yielded growth of the various organisms that were inoculated.
Conclusion:Breast milk does not have in vitro antibacterial effect although it may possess same in vivo with the synergistic effect of other substances in the body.

Keywords: in vitro, antibacterial effects, breast milk

How to cite this article:
Akujobi C N, Egbuonu I, Ezechukwu C C, Ogunsola F T. Determination of in-vitro antibacterial effects of breast milk. Niger Med J 2009;50:58-60

How to cite this URL:
Akujobi C N, Egbuonu I, Ezechukwu C C, Ogunsola F T. Determination of in-vitro antibacterial effects of breast milk. Niger Med J [serial online] 2009 [cited 2023 Sep 26];50:58-60. Available from: https://www.nigeriamedj.com/text.asp?2009/50/3/58/71948

   Introduction Top

Human milk is considered the ideal food for the new born during the first six months of life [1] . It is specifically adapted to the needs of the newborn infant [2].[3].[5] . It contains, in addition, a great array of 'bioactive factors' which provide the infant protection from infection by various micro-organism s [6],[7] , hormones, and growth factors that affect development, agents that modulate immune function [8] as well as anti inflammatory components [9] .

Protection against acute infections of the digestive and respiratory tract of breast fed infants were reported about two decades ago [10],[11] . Then in the 90's carefully designed studies confirmed without any doubt that breast feeding protects the newborn from diarrhea, respiratory tract infections and otitis media [12] and reduces incidence of necrotizing enterocolitis [13] .

Human milk contains anti-inflammatory agents such as antiproteases, antioxidants and enzymes that degrade inflammatory mediators and modulators of leukocyte activation [14] . It is said that colostrums, secreted during the first few days after parturition, contains higher concentrations of proteins (including higher levels of protective proteins such as secretory IgA, Lactoferrin, and Lysozyme) [15] . There is paucity of information on in vitro antibacterial effects of breast milk in Nigeria. The study was done to determine the antibacterial effects of breast milk on some common gram positive and gram negative organisms.

   Materials and Method Top

Study group: Thirty nine (39) breast feeding mothers who had a spontaneous vaginal delivery at term in Nnamdi Azikiwe University Teaching Hospital, Nnewi were used in the study.

Ethical issues: The research posed no health hazard to the patients and was at no extra cost to them. Participation was voluntary and participants were free to withdraw at any point in the study. Confidentiality of the patients was maintained. Ethical clearance was obtained from the Research and Ethics Committee of NAUTH.

   Methodology Top

The research was accompanied with a questionnaire, which was filled by the mother or the doctor with information from the mother. The questionnaire contained demographic information, and knowledge of and use of breast milk for the treatment of ailments.

Specimen collection: 2-3mls of breast milk was expressed directly into a sterile container. Samples were transported immediately to the laboratory for processing.

Test organisms include: Staphylococcus aureus, Klebsiella spp,  Escherichia More Details coli and Pseudomonas aeruginosa,

Control organisms include: Staph aureus
ATCC 29213 and Escherichia coli ATCC 25922.

Laboratory procedures:

Overnight cultures of test organisms and control organisms were ready prior to sample arrival in the laboratory. As soon as specimens arrived, 2-3 drops of each specimen was distributed in 7 dry sterile  Petri dish More Detailses. To each was then added 1 drop of either the test organisms or control strains standardized with 0.5 McFarlands standard. These were mixed very well. The mixture was sub cultured unto nutrient agar plates after 30 minutes, 1 hour and then finally 2 hours later. These plates were incubated over night then read the following day.

In the second method, overnight cultures of the organisms/ controls were plated out on agar plates. Then a sterile cork borer was used to make holes about 5mm diameter in the agar without puncturing the Petri dishes. Breast m ilk was dropped in the holes and this was incubated overnight as in the first method. The plates were examined the next day for zones of inhibition.

   Result Top

From the Questionnaire, 38 mothers (97%) said that they had heard about the use of breast milk for the treatment of ailments. Their source of information is seen in [Table 1]. Thirty three (84.6%) actually claimed they had used breast milk for treatment. Ailments used include conjunctivitis- 30 people (76%.9%), boils- 9 (23.1%) and umbilicus- 4 people (10.3%).
Table 1: Source of information about the use of breast milk for treatment of ailments.

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After 24 hours incubation period, there was luxuriant growth of the organisms on all the inoculated agar plates in both the first and second methods. There was no recognizable difference in the degree of growth of bacteria seen after 30 minutes, one hour and two hours contact times respectively in the first method. In the second method, where a cork borer was used to make holes in the agar plates and breast milk was introduced into the holes, after 24 hours of incubation, the inoculated organisms grew luxuriantly all over the agar plate. There was no zone of inhibition at all.

   Discussion Top

Hum an breast milk is the ideal food for the new born during the first six months of life. It offers babies complete nutrition, early protection against illness, safe and healthy food. It contains fat, proteins, carbohydrates, vitamins and minerals. Under normal circumstances, freshly expressed human milk has a mild, slightly sweet scent and may contain microbial non-pathogens of skin flora[16]. The study was done to ascertain if breast milk had in ­vitro anti bacterial effects on some common bacteria. It could be seen that there does not seem to be any anti bacterial activity in-vitro as the bacteria grew luxuriantly on all the plates that were incubated with no zones of inhibition.

It is also worthy of note that from the questionnaire, no medical doctor was said to have told the mothers about the topical use of breast milk in treatment of ailments. This could just be one of those myths being handed down from one generation to another without scientific basis. This does not in any way dispute the protection from the digestive as well as acute respiratory tract infections.

Studies have shown that protection from infection is provided by two main mechanisms classical immune protection provided by Immunoglobulins A, G and M in hum an milk [12] , as well as by a large array of other milk components that act as ligands for bacteria and viruses, and factors that fine tune the interaction among these agents which may also enhance the maturation of the infant's own potential. The protective agents in milk share several characteristics that enable them to be active in the infant[6]; they act at mucosal sites and are well adapted to resist the harsh environment of the gastrointestinal tract [hydrolytic enzymes, changes in gastric and pH, presence of bile salts]. Furthermore, action on microorganism is often accomplished synergistically and protection is achieved without triggering inflammatory reactions.

Non immune protection is provided by a large number of components in human milk that contrary to immune protection against specific antigens provided by milk immunoglobulins, protect in a non specific way and thus provide abroad spectrum of anti infective activity [17],[18],[19],[20],[21],[22],[23] .One of the proteins contained in milk-Lactoferrin has broad antimicrobial properties [24] .

   References Top

1.Hamosh M., Dewey K. G, Garza C. Nutrition during lactation. Washington National Academy Press. 1991. P.11.  Back to cited text no. 1
2.Picciano M. F. Human milk. Nutritional aspects of a dynamic food. Biol Neonate 1998; 74: 84.  Back to cited text no. 2
3.World Health Organization (WHO). Global Strategy for infant and young child feeding. Geneva. 2003. P 30  Back to cited text no. 3
4.Chan G M., Lee M. L. and Rechtman D. J. breast feeding Medicine. 2003, 2(4): 205-08.  Back to cited text no. 4
5.Mete E., Bavbek N., Dayi S., Erkmen M. and Andiran F. invitro antifirngal effect of human milk. Allergy Asthma Proc 2006; 27: 412-14.  Back to cited text no. 5
6.Stevens C. R., Miller T. M., Clinch J. G., Kanezler J. M., Bodamyali T. and Blake D. R. antibacterial properties of xanthine oxidase inhuman milk. The Lancet. 2000; 356: 829­-30.  Back to cited text no. 6
7.Goldman A. S. The immune system of human milk. Antimicrobial, anti-inflammatory and immunomodulating properties.  Back to cited text no. 7
8.Garofalo R. P., Goldman A. S. Cytokines, chemokines and colony stimulating factors in human milk. The 1997 update. Biol Neonate 1998; 74 :134.  Back to cited text no. 8
9.Garofalo R. P., Golgman A. S., Expression of functional immunomodulating and anti-inflammatory factors in human milk. Clin. Perinanatol 1999; 26: 361.  Back to cited text no. 9
10.Bauchner H., Levental J. M., Shapiro D. E. Studies on breast­feeding and infection. How good is the evidence? JAMA 1986; 256: 887.  Back to cited text no. 10
11.Villalpando S., Hamosh M. Early and late effects of breast feeding. Does breast feeding really matter? Biol Neonate 1998; 74: 177.  Back to cited text no. 11
12.Popkin B. M., Adair L., Akin J. S. Breast-feeding and diarrheal morbidity. Pediatrics 1990; 86: 274.  Back to cited text no. 12
13.Dewey K. G, Heinig M. J., Nommsem-Rivers L. A. Differences in morbidity between breast-fed and formula-fed infants. J Pediatr 1995; 126: 696.  Back to cited text no. 13
14.Goldman A. S., Thorpe L. W., Golgblum R. M. Anti­inflammatory properties of human milk. Acta Paediatr Scand 1986; 75: 698.  Back to cited text no. 14
15.Hamosh M., Hamosh P. Differences in composition of preterm, term and weaning milk, in Xanthou M (ed) New aspects of nutrition in infancy and prematurity. Amsterdam, Elsevier, 1987; 129-41.  Back to cited text no. 15
16.Igumbor E. O., Makura R. D., Makandirainba B. and Chihots V Storage of Breast milk: Effect of temperature and storage duration on microbial growth. Cent. AA J Med. 46(9): 247-51.  Back to cited text no. 16
17.Goldman A. S., Chheda S., Garofalo R. Evolution of immunologic functions of the gland and the postnatal development of immunity. Pediatr Res 1998; 43: 155.  Back to cited text no. 17
18.Hamosh M. Breast-feeding: Unraveling the mysteries of mother's milk. In Medscape Women's Health. http//:www. Medscape. Com 1996.  Back to cited text no. 18
19.Hamosh M. Protective functions of proteins and lipids in human milk. Biol Neonate 1998, 74: 163.  Back to cited text no. 19
20.Mestecky J., Blair C., Ogra P. L. (Eds): Immunology of milk and the neonate. New York, Plenum Press 1991, p 483.  Back to cited text no. 20
21.Newburg D. S., Neubauer S. H: Carbohydrates in milks: Analysis, quantities and significance. In RG Jensen (ed) of Milk Composition", San Diego, Academic Press 1995, p 273-349.  Back to cited text no. 21
22.Xanthou M., Bines J., Walker W A: Human milk and intestinal host defenses in newborns: An update. Adv Pediatr 1995, 42: 171.  Back to cited text no. 22
23.Xanthou M: Immune protection of human milk. Biol Neonate 1998; 74: 121.  Back to cited text no. 23
24.Tomita M., Takase M., Wakabayashi H: Antimicrobial peptides of lactoferrin. Adv Exp Med Biol 1994; 357: 209.  Back to cited text no. 24


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