Food Poisoning

If you’ve ever had a bout of food poisoning before, you will know how unpleasant it can be. Common symptoms include nausea, vomiting, diarrhoea and stomach cramps. Food poisoning occurs when you consume food contaminated with bacteria, viruses, parasites or the toxins they produce. Food poisoning is relatively common but can easily be prevented by the way you cook, store and handle your food. If you are unlucky enough to get food poisoning, probiotics can help you feel better quicker.

Symptoms of food poisoning

Symptoms can begin immediately, or within a few hours or even days of eating contaminated food. Symptoms can differ depending on what pathogen is present and can vary from mild to severe. When you get food poisoning, it usually lasts from 24 hours to 5 days, and typically involves one or more of the following:

• Nausea
• Vomiting
• Stomach cramps
• Diarrhoea
• Fever
• Headaches

Factors that contribute to food poisoning

Contamination of food can happen at any point of production: growing, harvesting, processing, storing, shipping or preparing. Factors that affect bacterial growth include:

• Time—the older the food, the more time bacteria has had to multiply. In ideal conditions this can happen very rapidly.
• Temperature—any foods kept within 5 °C and 60 °C are at higher risk. Think any food that isn’t kept very hot or refrigerated.
• Water—dried foods are at a much lower risk of contamination because bacteria need water to grow.
• Nutrients—most foods such as eggs, dairy and meat contain nutrients which promote microbes to multiply.
• pH—most foods are a neutral pH which most bacteria grow well in. Foods that are either acidic or alkaline usually deter the growth of pathogens.

Menacing micro-organisms

Many bacterial, viral or parasitic agents cause food poisoning. The following information shows some of the possible culprits, when you might start to feel symptoms and common ways the organism is spread.

Campylobacter

Campylobacter is one of the leading causes of food poisoning-related hospitalisation in Australia.

This bacterium is commonly found in meat and poultry contaminated with animal faeces. Other sources include unpasteurised milk and water. Symptoms usually begin within 2-5 days.

Bacillus cereus

Bacillus cereus is a spore-producing bacterium responsible for two different toxins — one that causes vomiting and another that causes diarrhoea. Cooked foods become contaminated with the toxins when they are not stored at the correct temperature. Rice, vegetables, meat, fish and milk are common foods that may contain this bacterium. The incubation period is 30 minutes to five hours for the vomiting toxin and eight to 16 hours for the diarrhoeal toxin.

E. coli

E. coli (Escherichia coli) are bacteria that live in the gut of humans and animals. They are mostly harmless, but some strains produce toxins that cause illness. E. coli can be present in undercooked meat and smallgoods, unpasteurised milk, fruit juices, vegetables and sprouts. The incubation period is two to eight days and symptoms usually last five to 10 days.

Hepatitis A virus

Hepatitis A virus causes inflammation of the liver. Symptoms can include fever, tiredness, loss of appetite, nausea, stomach pains, dark urine and jaundice. Raw, ready to eat foods such as salads, and oysters grown in contaminated water are possible sources. Contamination occurs because food has been handled by an infectious person. The incubation period is 15 to 50 days and the symptoms usually last several weeks.

Listeria

Listeria is a bacterial infection that can be obtained from hot dogs, luncheon meats, raw seafood, unpasteurized milk and cheeses and unwashed raw produce. The incubation period is three to 70 days.

Salmonella

Salmonella is a bacterial infection that can make you very unwell. It is found in raw eggs, milk, poultry, red meat, unwashed salads, shellfish and oysters. The incubation period is six to 72 hours and symptoms usually last for two to seven days, but you can be infectious for several weeks.

How can I prevent food poisoning?

Always wash your hands with soap and hot water before preparing food, after handling raw food and before eating. Use hot, soapy water to wash utensils, cutting boards and surfaces where food is prepared.

Store and handle your food safely, using strategies such as separating raw and ready-to-eat foods, keeping hot food hot (over 60C) and cold food cold (under 5C), cooking and reheating foods thoroughly, refrigerating food within two hours of cooking and thoroughly washing fruit and vegetables. When travelling avoid uncooked food, non-bottled drinks and unpasteurised milk. 

Use food well within the use by date and if in doubt throw it out.

Probiotics

Taking a good quality probiotic can help prevent you falling very ill from food poisoning. If you are sick, it can reduce the amount of days unwell and prevent damage to the digestive system. It’s always a good idea to travel with probiotics to avoid food poisoning while away and at a higher risk of eating contaminated food. Probiotics have been demonstrated to be effective in antagonizing foodborne pathogens—with the most efficacious strains being L. Rhamnosus LGG, L. acidophilus, L. casei, L. fermentum, L. plantarum and Saccharomyces boulardii.

Fermented foods

Foods that are fermented from vegetable and milk products provide a range of health benefits—one of which being their ability to reduce pathogens in the gut due to the production of antimicrobial compounds such as bacteriocin and nisin. Species of beneficial bacteria isolated from kimchi (traditional fermented Korean dish) show strong antimicrobial activity against Listeria monocytogenes, Staphylococcus aureus, E. coli, and Salmonella typhimurium. 

Weissella cibaria isolated from fermented cabbage (sauerkraut) shows antimicrobial activity against Gram-positive and Gram-negative pathogens.

Several lactic acid bacteria species isolated from Romanian traditional fermented fruits and vegetables have antimicrobial activity against L. monocytogenes, E. coli, Salmonella, and Bacillus.

Other suggestions when sick

Drinking peppermint, chamomile, ginger or fennel tea can help to reduce abdominal pain, nausea and an unsettled stomach. Rest as much as possible and eat small, plain meals such as rice crackers, cooked rice, potatoes or soup. Remember to prevent dehydration by taking small, frequent sips of water and use an electrolyte supplement if necessary.

References

1. https://www.mayoclinic.org/diseases-conditions/food-poisoning/symptoms-causes/syc-20356230
2. https://www.betterhealth.vic.gov.au/health/healthyliving/food-poisoning-prevention
3. Amalaradjou MA, Bhunia AK. Bioengineered probiotics, a strategic approach to control enteric infections. Bioengineered. 2013 Nov-Dec;4(6):379-87 https://www.ncbi.nlm.nih.gov/pubmed/23327986
4. Amalaradjou MA, Bhunia AK. Modern approaches in probiotics research to control foodborne pathogens. Adv Food Nutr Res. 2012;67:185-239 https://www.ncbi.nlm.nih.gov/pubmed/23034117
5. Tamang JP, et al. Functional Properties of Microorganisms in Fermented Foods. Front Microbiol. 2016 Apr 26;7:578 https://www.ncbi.nlm.nih.gov/pubmed/27199913