Team:XHD-Wuhan-Pro-China/Model
Model
Objective
At present, the number of long-term drinking in the world is increasing. About 2 billion people drink regularly, and around 3 million people worldwide are killed each year due to excessive drinking. The number of deaths has exceeded the total number of deaths from AIDS, violence, and traffic accidents. More and more people are becoming victims of alcohol. The families and communities of alcoholics have a potential drinking violence crisis at any time. At the same time, alcohol is also harming the physical and mental health of drinkers. People may drink because of the pressure in life, but drinking will also make people more inefficient. People who drink too much will not only harm their bodies, such as their liver, stomach, and brain. People may suffer from chronic gastritis and gastric ulcer. Excessive drinking will also damage people's central nervous system and reduce people's memory. In addition, excessive alcohol can hurt others. When a certain amount of alcohol is drunk, the human body will be excited and difficult to suppress or lose self-control. In this case, people will lose their reason, injure others by mistake, destroy social security, and so on, leading to the crime rate.
Our project aims to enable people who drink too much to reduce the harm of alcohol to the liver by using our products and allow these people to be relatively rational and not do anything harmful to themselves and social security. Our project is to construct probiotics containing ADH gene-producing ADH and ALD gene-producing ALDH. Probiotics are colonized in the human intestine. Our product development enables probiotics to synthesize ADH and ALDH in the stomach and intestines, reduce alcohol damage to the liver, prevent alcohol poisoning, and reduce the harm caused by alcohol to people worldwide.
Since the goal of our project is that probiotics can reduce diseases and hazards caused by alcohol, the purpose of our mathematical modeling is to obtain a ratio between the absorption of alcohol by our human body. Then, we can get that the absorption of alcohol by engineered probiotics and know the number of probiotics we should take after drinking. In this way, if people take more engineered probiotics, more alcohol will be absorbed by probiotics, not the stomach. When we take less engineered probiotics, more alcohol will be absorbed by the stomach. The model allows people to see how probiotics affect how much alcohol is absorbed by the body more intuitively.
Assumptions
In this mathematical modeling, we assume that a person drinks 250ml 50 ℃ liquor at one time and calculate how many engineered probiotics he needs to take to prevent most alcohol from being absorbed by the stomach to reduce the damage of alcohol to the liver and to avoid alcoholism.
Model Development
Step 1: Calculate the Diluted Concentration of Alcohol after Drinking
First, we searched ordinary people for the gastric volume, then determined how much the 250 ml 50-degree liqueur concentration would be diluted in the stomach after drinking.
Step 2: How fast does the Human Body Absorb Alcohol
Ethanol can be absorbed in the digestive tract without digestion, which is fast and complete. Generally, 20% is absorbed in the stomach, and the duodenum and jejunum absorb the remaining 80%. The absorption rate of alcohol depends on several factors. Whether there is food in the stomach, the functional status of the gastric arm, the amount of alcohol in the beverage, and drinking habits can affect the absorption of alcohol. For example, drinking alcohol on an empty stomach and the alcohol concentration is 20-30% is the fastest. When drinking on an empty stomach, absorb about 50% in 15 minutes, 60% - 90% in half an hour, and 100% in 2-3 hours. Therefore, 3-8% beer with an alcohol concentration of about 20% can increase the alcohol content in the blood faster, while spirits with an alcohol concentration of about 40% can delay gastric emptying and inhibit absorption.
Step 3: Calculate the Degradation Rate of Engineered Probiotics
1. Test results of tolerance of engineering strains to ethanol and acetaldehyde
In this study, two engineering strains E.coli pSB-AA and E.coli pSB-AN were constructed. In order to test their performance in degrading ethanol and acetaldehyde, some in vitro abilities of the two engineering strains were tested.
Firstly, the growth curves of engineering strains E.coli pSB-AA and E.coli pSB-AN in media containing different concentrations of ethanol and acetaldehyde were drawn to show the tolerance of engineering strains to ethanol and acetaldehyde. As shown in Fig. 1 and Fig. 2, when the concentration of ethanol greater than 6% and the concentration of acetaldehyde greater than 0.3%, the growth of bacteria E.coli 1917 will be seriously inhibited. When ethanol concentration greater than 8% and acetaldehyde concentration greater than 0.4%, the growth of engineering strain E.coli pSB-AA was inhibited, and the tolerance of E.coli pSB-AA to ethanol and acetaldehyde was improved to a certain extent. When the concentration of ethanol was greater than 10% and the concentration of acetaldehyde was greater than 0.5%, the growth of engineering strain E.coli pSB-AN was inhibited. It can be seen that the tolerance of E.coli pSB-AN to ethanol and acetaldehyde was significantly improved.
2.Test results of the ability of engineering strains to degrade ethanol and acetaldehyde
In order to alleviate the damage caused by excessive drinking, the ability of engineering strains to degrade ethanol and acetaldehyde is very important. We measured the changes of ethanol or acetaldehyde content in the medium after different strains grew in different concentrations of ethanol and acetaldehyde for 14 hours, so as to measure the degradation ability of the strains to ethanol and acetaldehyde. As shown in Figure 3, when the ethanol content is 2% and the acetaldehyde content is 0.1%, the degradation efficiency is the highest. For E.coli pSB-AA, the degradation rates of ethanol are 54.3%, the degradation rates of acetaldehyde are 41.4%. For E.coli pSB-AN, the degradation rates of ethanol are 61.5%, the degradation rates of acetaldehyde are 53.5%. However, with the increase of the concentration of ethanol and acetaldehyde, the growth and metabolism of bacteria are also inhibited, so the degradation ability of bacteria to ethanol and acetaldehyde is also gradually reduced.
