Babies’ immune systems are still developing, and sometimes it can seem that they pick up every cough and cold that’s going around, especially if they go to daycare or have older siblings.
While children generally recover well from infections, the best way to keep your child healthy is through prevention. Following good handwashing practices, especially with visitors, prevents the spread of infection. Following BC’s immunization schedule and staying up to date with vaccinations is another important way to prevent infection.
Most of the common illnesses that infants and young children get are colds and flu, which are caused by viruses. Viral infections cannot be treated by antibiotics and are often best managed at home.
When to seek help:
If a baby under 3 months has a cough or fever
If your child has trouble breathing
Some other illnesses are caused by bacteria, and many of these can also be managed at home but may require antibiotics. It’s important to remember that some conditions do need antibiotics to resolve safely, and that your healthcare provider has been trained to determine when antibiotics are the right choice. Having a conversation with your healthcare provider about when antibiotics are needed can help you feel confident in the decisions you are making together.
Antibiotic side effects and the microbiome
If your baby’s care healthcare provider prescribes antibiotics, it’s important to follow the directions on the bottle. Oral antibiotics often have side effects like upset tummy and diarrhea that can be uncomfortable for a baby and their parents. These side effects are not an allergic reaction, and it is safe to continue the treatment.
These tummy side effects happen because antibiotics don’t only kill the bad bacteria; they also kill a lot of the good bacteria we all have in our gut, the gut microbiome. The microbiome is a community of hundreds of types of good bacteria that help us digest food. The microbiome also supports the development of a healthy immune system in babies and young children. Learn more about the bacteria that make up our gut microbiome.
Antibiotics and Asthma
New research in BC and Manitoba has found a strong link between antibiotic use in babies and asthma and other allergic conditions later in childhood.
The researchers looked at the health records of over 475,000 children and could see an increased chance of asthma diagnosis in children who had been given antibiotics as babies.
This increased chance occurred even after accounting for other factors that influence asthma, including parents’ history of asthma, air quality, and type of infection the baby had.
This is due to antibiotics killing good bacteria in the gut microbiome at a time when gut bacteria are needed to help the immune system develop properly.
Breastmilk and antibiotics
Other research has shown that if a baby does need antibiotics, breastmilk can help replenish the good bacteria of the gut more quickly. This is because breastmilk is a natural “microbiome starter kit” containing good bacteria (probiotics) to help seed the gut microbiome, along with special sugars (prebiotics) that feed good bacteria in the gut. Breastfeeding can help reduce the possibility of asthma diagnosis later in life. This benefit is stronger with longer and more exclusive breastfeeding, directly at the breast – but any amount of breastmilk is helpful, whether it’s pumped or supplemented with formula.
If you are planning to breastfeed, check out local support options early in case they are needed:
Your local public health unit’s lactation services
Your midwife or primary care provider
811 to request free lactation consultations
BC Lactation Consultant Association to find support near you
FAQs
The study looks at patterns across groups of children, so it cannot predict what will happen to any individual child. Breastmilk for any amount of time provides many benefits. Longer duration is linked to greater benefit, but there is no single cutoff point where these benefits end. The strongest effects are seen early in infancy – so your milk made a difference!
Our study clearly found a risk associated with antibiotic use regardless of the type of infection. This allows us to conclude that antibiotics directly affect the risk. It remains possible that some respiratory infections also contribute to risk.
The largest effect is in infants under one year. The link is less strong for older babies and toddlers. It’s always important to only use antibiotics when they are really needed.
Antibiotics can pass from the mother into her milk, and this can have an impact on baby’s gut microbiome. However, the benefits of breastfeeding strongly outweigh that risk for most antibiotics. When it comes to longer term health effects, it seems that antibiotics given directly to the baby confer the greatest risk.
Any amount of breast milk provides benefits for your baby, including supporting immune development and the gut microbiome.
Research shows that feeding directly at the breast is associated with the lowest risk of conditions like asthma. Mixed feeding (breast milk and formula) is associated with higher risk than exclusive breastfeeding, but lower risk than exclusive formula feeding.
Many families use a combination of feeding methods. When formula is used, continuing to provide breast milk still offers important benefits.
Calling 8-1-1 is the best resource for determining when your baby needs to see a healthcare provider if you are unsure. If it is an emergency, call 9-1-1.
References
Thomas SP, Denizer E, Zuffa S, Best BM, Bode L, Chambers CD, Dorrestein PC, Liu GY, Momper JD, Nizet V, Tsunoda SM, Tremoulet AH. Transfer of antibiotics and their metabolites in human milk: Implications for infant health and microbiota. Pharmacotherapy. 2023 May;43(5):442-451. doi: 10.1002/phar.2732. Epub 2022 Oct 18. PMID: 36181712; PMCID: PMC10763576.
Hoskinson C, Medeleanu MV, Reyna ME, Dai DLY, Chowdhury B, Moraes TJ, et al. Antibiotics taken within the first year of life are linked to infant gut microbiome disruption and elevated atopic dermatitis risk. J Allergy Clin Immunol. 2024 Jul;154(1):131–42.
Arrieta MC, Stiemsma LT, Dimitriu PA, Thorson L, Russell S, Yurist-Doutsch S, et al. Early infancy microbial and metabolic alterations affect risk of childhood asthma. Sci Transl Med. 2015 Sep 30;7(307):307ra152.
Hoskinson C, Dai DLY, Del Bel KL, Becker AB, Moraes TJ, Mandhane PJ, et al. Delayed gut microbiota maturation in the first year of life is a hallmark of pediatric allergic disease. Nat Commun. 2023 Aug 29;14(1):4785.
Laforest-Lapointe I, Arrieta MC. Patterns of Early-Life Gut Microbial Colonization during Human Immune Development: An Ecological Perspective. Front Immunol [Internet]. 2017 Jul 10 [cited 2024 Nov 11];8. Available from: https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2017.00788/full
Donald K, Finlay BB. Early-life interactions between the microbiota and immune system: impact on immune system development and atopic disease. Nat Rev Immunol. 2023 Nov;23(11):735–48.
Duong QA, Pittet LF, Curtis N, Zimmermann P. Antibiotic exposure and adverse long-term health outcomes in children: A systematic review and meta-analysis. J Infect. 2022 Sep 1;85(3):213–300.
Dai DLY, Petersen C, Hoskinson C, Del Bel KL, Becker AB, Moraes TJ, et al. Breastfeeding enrichment of B. longum subsp. infantis mitigates the effect of antibiotics on the microbiota and childhood asthma risk. Med N Y N. 2023 Feb 10;4(2):92-112.e5.
Dai D, Manus M, Hoskinson C et al. Breastfeeding may lessen socioeconomic disparities in child health through differences in the infant gut microbiome. Cell Reports Medicine, 2026; 7
Azad MB, Vehling L, Lu Z, Dai D, Subbarao P, Becker AB, et al. Breastfeeding, maternal asthma and wheezing in the first year of life: a longitudinal birth cohort study. Eur Respir J. 2017 May;49(5):1602019.
Shenhav L, Fehr K, Reyna ME, Petersen C, Dai DLY, Dai R, et al. Microbial colonization programs are structured by breastfeeding and guide healthy respiratory development. Cell. 2024 Sep 19;187(19):5431-5452.e20.
Patrick DM, Sbihi H, Dai DLY, Al Mamun A, Rasali D, Rose C, et al. Decreasing antibiotic use, the gut microbiota, and asthma incidence in children: evidence from population-based and prospective cohort studies. Lancet Respir Med [Internet]. [cited 2020 Jul 13]; Available from: https://doi.org/10.1016/S2213-2600(20)30052-7
Mamun AA, Zou C, Lishman H, Stenlund S, Xie M, Chuang E, et al. Association between antibiotic usage during infancy and asthma incidence among children: a population-level ecological study in British Columbia, Canada. Front Allergy. 2024;5:1456077.
Lishman H, Nickel NC, Sbihi H, Xie M, Mamun A, Zhang BY, et al. Investigating the effect of early life antibiotic use on asthma and allergy risk in over 600 000 Canadian children: a protocol for a retrospective cohort study in British Columbia and Manitoba. BMJ Open. 2023 Apr 4;13(4):e067271.
Lishman H. The impact of antibiotic use in infancy on asthma and allergy incidence in 600,000 Canadian children: retrospective cohort studies in British Columbia and Manitoba. 42nd Annual Meeting of the European Society for Paediatric Infectious Diseases; 2024 May 22.
Medeleanu MV, Reyna ME, Dai DLY, Winsor GL, Brinkman FSL, Verma R, et al. Exploring the potential mediating role of systemic antibiotics in the association between early-life lower respiratory tract infections and asthma at age 5 in the CHILD study. Front Allergy [Internet]. 2025 Jan 21 [cited 2026 Jan 27];5. Available from: https://www.frontiersin.org/journals/allergy/articles/10.3389/falgy.2024.1463867/full
Lee TY, Petkau J, Saatchi A, Marra F, Turvey SE, Lishman H, et al. Impact analysis of infant antibiotic exposure on the burden of asthma: a simulation modeling study. Front Allergy [Internet]. 2024 Dec 23 [cited 2026 Jan 27];5. Available from: https://www.frontiersin.org/journals/allergy/articles/10.3389/falgy.2024.1491985/full
Microbiome – How trillions of microorganisms work to keep you healthy
What is the microbiome?
We have trillions of bacteria living in our bodies. Different groups of bacteria live in different parts of the body (skin, mouth, nose, reproductive system, digestive tract), with the vast majority in the gut. They all work to keep us healthy.
Most of our bacteria are helpful to us and are sometimes called “good bacteria” or our “microbiome”.
The word microbiome comes from the Greek micro – meaning small, and bios – meaning life. The term describes the microorganisms, like bacteria, viruses and fungi, that live on and in a person’s body and all around us.1
Each individual has a their own microbiome, much like a fingerprint.
Many factors such as diet, environment, having pets and our overall health affect our microbiome.
Our microbiome is priceless to us
Bacteria have always lived on and in our bodies and are necessary for good health.1
Bacteria in our gut help us digest our food, train our immune system, and even help our brain develop.
The good bacteria take up space and crowd out disease-causing harmful bacteria.
The good bacteria contain far more genes than our human genome and produce important components for our body such as vitamin K (blood health) and serotonin (nerve health).1
Although we don’t understand exactly how, it seems that changes to our microbiome could result in diseases such as asthma, inflammatory bowel disease and Parkinson’s Disease.1
Our bodies contain more bacterial than human cells and genes
Eat a balanced diet rich in fibre, whole grains, fruits and vegetables.2,3 These provide a food source for the good bacteria in your gut. Dietary fibre is sometimes referred to as a form of “prebiotic” as it assists in the growth of these good bacteria.
Fermented (probiotic) foods such as cultured milk products (certain yogurts), miso, kimchi and sauerkraut contain beneficial live bacteria that can sometimes have a helpful effect on the microbiome.4,5
Exercise is thought to have a helpful effect on the microbiome; however, one study found that high intensity endurance training might be harmful to the microbiome.7
Wash your hands often with plain soap (no need for antibacterial soap) which protects you against illness and from getting harmful bacteria into your body. It’s especially important to wash your hands after you have been to the washroom, before you eat, when you’ve been in public spaces and after coughing or sneezing.
Stay up to date with immunizations and immunize your children to avoid the need for antibiotics.
Take antibiotics when you understand you have a bacterial infection that requires antibiotics. Antibiotics do not work against viruses.
Antibiotics are designed to kill the bacteria causing an infection, but they also kill many of the good bacteria. Antibiotics cause the most damage to the microbiome compared to any other factor.1 When your microbiome is affected by antibiotics, it takes time for the good bacteria to grow back, and repeated antibiotic exposure permanently harms your microbiome.10
Sometimes when a lot of good bacteria are killed, potentially harmful bacteria can grow and cause infection, such as bad diarrhea from a bacterium called Clostridioides difficile (C. diff.).11
Some sources suggest that an animal-based diet (which is composed of red meats, eggs and cheeses, and processed foods such as white sugar and flour) can weaken the microbiome when compared to a plant-based diet, which is rich in grains, legumes, fruits and vegetables.2
The current evidence about probiotics
Probiotics are supplements that contain live bacteria that have a potential health benefit.
Current research does not show that probiotic supplements available on the market have an impact on restoring the bacterial diversity of the gut microbiome following antibiotic treatment.12 In contrast, some research suggests that probiotics can even direct the microbiome towards less diversity if taken after the microbiome was harmed by antibiotics.13 The best way to restore the microbiome after taking antibiotics is improved diet, exercise, and exposure to microbes (through pets, nature, etc.).
Some studies show that specific types of bacteria can help certain diseases. As with any supplement, you should talk to your healthcare provider if you have questions, especially for young children, older adults, and people with weakened immune systems.
Research related to manipulating or altering the gut microbiome to prevent or treat disease is ongoing and in the future may involve clinically administered pre/probiotics that are specific to the underlying imbalance.14
Prebiotics are substances that feed the good bacteria in the gut. Fibres from whole grain, fruits and vegetables are excellent prebiotics. However, there are no scientific studies demonstrating a defined benefit for prebiotics yet.
Commercially sold probiotics are not regulated by Health Canada, so are not as rigourously tested as medicines. Therefore, their quality cannot be guaranteed and the health effects have not been studied for many of them.
Special groups
Infants
Infants start to develop their gut microbiome in the womb, during birth when they pass through the birth canal and through skin-to-skin exposure with their caregivers. Breastmilk/human milk also plays a key role in developing an infants’ microbiome.15
In the first few months of life a healthy microbiome is very important in helping to develop a healthy immune system.
Disruptions to the gut bacteria at this age can have impacts on immune system development and leave children susceptible to allergic diseases (such as asthma) later in childhood.16,17
Healthcare providers are careful about using antibiotics for infants because their developing microbiome is especially susceptible to disruption.
Feeding with breastmilk/human milk throughout infancy helps to establish and protect the microbiome, even when antibiotics may be needed.18
Older Adults
As we age, the number of different microorganisms in our microbiome decreases.19
This means the microbiome is less able to keep bad bacteria from spreading and can lead to a higher risk of some infections, such as C. difficile infection.
An ageing microbiome also recovers slower from the effects of antibiotics
It is important to only take antibiotics when they are prescribed to you by a health care provider. This protects your microbiome and minimizes interactions with other medications.
Gilbert JA, Blaser MJ, Caporaso JG, Jansson JK, Lynch S V., Knight R. Current understanding of the human microbiome. Nat Med. 2018;24(4):392-400. doi:10.1038/nm.4517
David LA, Maurice CF, Carmody RN, et al. Diet rapidly and reproducibly alters the human gut microbiome. Nature. 2014;505(7484):559-563. doi:10.1038/nature12820
Wu GD, Chen J, Hoffmann C, et al. Linking Long-Term Dietary Patternswith Gut Microbial Enterotypes. Science (80- ). 2011;334(October):105-109. doi:10.1126/science.1208344.
Taylor BC, Lejzerowicz F, Poirel M, et al. Consumption of Fermented Foods Is Associated with Systematic Differences in the Gut Microbiome and Metabolome. mSystems. 2020;5(2). doi:10.1128/msystems.00901-19
Leeuwendaal NK, Stanton C, O’toole PW, Beresford TP. Fermented Foods, Health and the Gut Microbiome. Nutrients. 2022;14(7):1-26. doi:10.3390/nu14071527
Ortiz-Alvarez L, Xu H, Martinez-Tellez B. Influence of Exercise on the Human Gut Microbiota of Healthy Adults: A Systematic Review. Clin Transl Gastroenterol. 2020;11(2):e00126. doi:10.14309/ctg.0000000000000126
Bonomini-Gnutzmann R, Plaza-Díaz J, Jorquera-Aguilera C, Rodríguez-Rodríguez A, Rodríguez-Rodríguez F. Effect of Intensity and Duration of Exercise on Gut Microbiota in Humans: A Systematic Review. Int J Environ Res Public Health. 2022;19(15). doi:10.3390/ijerph19159518
Maillard JY, Pascoe M. Disinfectants and antiseptics: mechanisms of action and resistance. Nat Rev Microbiol. 2024;22(1):4-17. doi:10.1038/s41579-023-00958-3
Yang QE, Ma X, Li M, et al. Evolution of triclosan resistance modulates bacterial permissiveness to multidrug resistance plasmids and phages. Nat Commun. 2024;15(1). doi:10.1038/s41467-024-48006-9
Modi SR, Collins JJ, Relman DA. Antibiotics and the gut microbiota. J Clin Invest. 2014;124(10):4212-4218. doi:10.1172/JCI72333
Brown KA, Khanafer N, Daneman N, Fisman DN. Meta-analysis of antibiotics and the risk of community-associated Clostridium difficile infection. Antimicrob Agents Chemother. 2013;57(5):2326-2332. doi:10.1128/AAC.02176-12
Éliás AJ, Barna V, Patoni C, et al. Probiotic supplementation during antibiotic treatment is unjustified in maintaining the gut microbiome diversity: a systematic review and meta-analysis. BMC Med. 2023;21(1):1-18. doi:10.1186/s12916-023-02961-0
Suez J, Zmora N, Zilberman-Schapira G, et al. Post-Antibiotic Gut Mucosal Microbiome Reconstitution Is Impaired by Probiotics and Improved by Autologous FMT. Cell. 2018;174(6):1406-1423.e16. doi:10.1016/j.cell.2018.08.047
Cunningham M, Azcarate-Peril MA, Barnard A, et al. Shaping the Future of Probiotics and Prebiotics. Trends Microbiol. 2021;29(8):667-685. doi:10.1016/j.tim.2021.01.003
Fehr K, Moossavi S, Sbihi H, et al. Breastmilk Feeding Practices Are Associated with the Co-Occurrence of Bacteria in Mothers’ Milk and the Infant Gut: the CHILD Cohort Study. Cell Host Microbe. 2020;28(2):285-297.e4. doi:10.1016/j.chom.2020.06.009
Donald K, Finlay BB. Early-life interactions between the microbiota and immune system: impact on immune system development and atopic disease. Nat Rev Immunol. 2023;23(11):735-748. doi:10.1038/s41577-023-00874-w
Patrick DM, Sbihi H, Dai DLY, et al. Decreasing antibiotic use, the gut microbiota, and asthma incidence in children: evidence from population-based and prospective cohort studies. Lancet Respir Med. 2020;8(11):1094-1105. doi:10.1016/S2213-2600(20)30052-7
Dai DLY, Petersen C, Hoskinson C, et al. Breastfeeding enrichment of B. longum subsp. infantis mitigates the effect of antibiotics on the microbiota and childhood asthma risk. Med. 2023;4(2):92-112.e5. doi:10.1016/j.medj.2022.12.002
Bosco N, Noti M. The aging gut microbiome and its impact on host immunity. Genes Immun. 2021;22(5-6):289-303. doi:10.1038/s41435-021-00126-8
Antibiotic Resistance, Overuse and Misuse in Adults Over 65
Misinformation about antibiotics leads to overuse, misuse and resistance
Antibiotics are the most common treatment for bacterial infections. They don’t work for viral infections like colds, flu or COVID-19. Antibiotic resistant bacteria develop if you take antibiotics when you don’t need them. When these bacteria spread, it undermines modern medicine.
Why should adults over 65 be concerned about antibiotic resistance?
If you are over 65 years of age you are more likely to have an infection. You may have a weakened immune system or live in a care home in close contact with others who may be ill.
As well, you may visit health care settings like hospitals more often. Infections can spread easily in these settings. Antibiotics may also interact with other medications you are already taking.
What you can do to prevent antibiotic resistance
If you are being prescribed antibiotics, ask your health-care provider about the best option for you.
If prescribed antibiotics, discuss with your health-care provider side effects and interactions with other medications.
Always follow your health-care provider’s directions on how to take antibiotics.
Reduce the spread of infections to help yourself and others.
Reducing and preventing the spread of infections in the first place decreases the need for antibiotics, and will help us all to stay healthier.
Wash your hands often with plain soap and water.
Clean common surfaces with regular cleaner and water – you don’t need antibacterial cleaners for most home cleaning.
Store, handle and prepare food safely.
Sneeze into a sleeve or tissue to avoid spreading germs
Stay active and develop healthy habits to keep your immune system strong.
Download and display this poster in your practice.
Penicillin Allergy – Things You Need to Know
What is penicillin?
Penicillin is one of the first antibiotics discovered, and has been used for nearly 80 years to treat common bacterial infections such as bronchitis and laryngitis. It is inexpensive and can treat skin, ear, sinus and upper respiratory tract infections.
Penicillin is one of the safer antibiotics
Compared to other antibiotics, penicillin can be more effective and less likely to result in antibiotic-resistant bacteria. It also has a lower risk of causing C. difficile infection, a severe and hard to treat diarrhea.
Do you have a penicillin allergy?
You may have had a reaction when taking penicillin in the past in the form of hives, itchiness, rashes or swelling. These are common side effects and do not necessarily indicate an allergy. Fewer than 5 in 10,000 people have a true penicillin allergy.
In fact, 80 per cent of adverse effects related to penicillin disappear over time. This means that you may be able to take penicillin safely again the next time you need it, even if you have had reactions to the antibiotic in the past.
Should you take penicillin?
Always share any past penicillin reactions with your health-care provider. They will let you know if you should try penicillin again or use another antibiotic. While your health-care provider may avoid prescribing you penicillin, they may also determine that it is safe to try again.
This is important as the alternatives to penicillin are often stronger antibiotics which may have a higher risk of side effects and should be saved for times when they are truly needed. If these alternative antibiotics are used too much, bacteria may develop resistance to these drugs, and they may not work in future.
Penicillin allergy and what you can do
Before asking to be prescribed a different antibiotic, talk to your health-care provider. They will be able to evaluate your allergy or refer you to an allergist.
Did you know that half of all penicillin allergies go away within 5 years? Learn more about why penicillin may still be the right choice even if you have been told you have an allergy.
Patient and provider information on antibiotic allergies.
Using Antibacterial Products at Home
Using antibacterial products in your home washes away the good bacteria
Millions of good bacteria live on our bodies to protect against infections caused by bad bacteria. Good bacteria also keep harmful bacteria from multiplying. Antibacterial cleaners, makeup and body products wash away the good and the bad. Antibacterial use makes bacteria more resistant to antibiotics.
Using antibacterial products in your home impacts hospital disinfectants
Researchers have found little difference between using plain soap or antibacterial soap in a home or community setting and there is no added benefit of using antimicrobial soap in preventing infections. Similarly, antibacterial ingredients added to makeup, hygiene products, and surfaces of children’s toys have no added benefit to protect against the common cold or the flu. Moreover, some antimicrobial chemicals (such as Triclosan) are harmful to plants and animals when the chemicals are washed down the drain. Triclosan also kills good bacteria and can cause antibiotic resistance over time.
What household products may be labelled as antibacterial, antimicrobial or antiseptic?
Soaps and cleaners
Disinfectant wipes
Window cleaners
Cleaning cloths
Toothpastes
Mouthwashes
Facial cleaners
Makeup and makeup brushes
Pillowcases
Garbage bags and plastic wrap
Child and baby products
What are alternatives to antibacterial products?
Plain soap or detergent and water (any temperature) are the only tools you need to get things clean. Most households don’t need antibacterial cleaning products.
There’s little difference between plain soap versus antibacterial soap when you’re at home. Antibacterial ingredients don’t protect you better from cold or flu. Handwashing with plain soap is extremely effective at reducing the spread of germs.
The David Suzuki Foundation have provided alternative non-toxic disinfecting solutions for at-home use.
Antibiotics for Cold, Flu and COVID-19
Antibiotics for cold, flu and COVID-19 do not work
Antibiotics treat bacterial infections. Colds, COVID-19 and the flu are viral infections, so antibiotics won’t help. Using antibiotics when you have these illnesses can lead to the development of antibiotic resistant bacteria.
There are a few ways to help prevent colds, flu and COVID-19
The best way to recover from a cold or flu is to drink plenty of fluids, get rest, and give your body time to do its job.
Do I have COVID-19?
If you experience any of these symptoms, stay home and contact your healthcare provider. You may just have a cold or the flu but stay home to keep others safe. Here is a link to the BC COVID-19 Self-assessment Tool.
Symptoms of COVID-19 include new or worsening:
Fever or chills
Cough
Loss of sense of smell or taste
Difficulty breathing
Sore throat
Loss of appetite
Runny nose
Sneezing
Extreme fatigue or tiredness
Headache
Body aches
Nausea or vomiting
Diarrhea
COVID-19 symptoms can range from mild to severe. Sometimes people with COVID-19 have mild illness, but their symptoms may suddenly worsen in a few days.
Go to an urgent care clinic or emergency department if you:
Antibiotics don’t help most respiratory infections, and they can even be harmful. See ways you can help treat symptoms from colds and flu without unnecessary antibiotics.
